chore: add "gen" target as a pre build script (aws#10648)

### What's new?

1. Added `.scripts/gen.sh` - execute this to execute `gen` all modules, for cfn modules this will usually execute `cfn2ts`.  This also means that you can use it to generate all required files to build `monocdk`:

```
./scripts/gen.sh
lerna build --scope monocdk
```
 
2. `cdk-build` will now execute the command specified in the package `script.gen` directive.
3. `cdk-build.pre` - The commands in the `pre` array are now concatenated using `&&`. 

This PR includes changes to many files the majority of them are `package.json` files. Summary of changes:

1. Added a `gen` as an npm script target to all cfn modules. The `gen` target is already used in our repo as a convention for executing pre build command for code generation. This change extends it to  include executing `cfn2ts`. Prior to this change we were executing the `pre` commands in `cdk-build`, followed by executing `cfn2ts` on cfn modules. `cdk-build` now execute `gen` unless `--skip-gen` is passed.
2. All code generation command (non `cfn2ts`) were moved from `pre` in `cdk-build` to `gen`. The only remaining `pre` directives are those unrelated to code generation such as cleaning commands.
**Why?**
This will allow us to execute `lerna run --stream gen` to execute all required code generation scripts on all modules.
2. The `cfn2ts` script **already** includes the ability to auto detect the CloudFormation scope from `cdk-build` clause in the `package.json`:
https://github.com/aws/aws-cdk/blob/bc096f08dd1dc29a0bb320b5798b0d7bee5e3161/tools/cfn2ts/bin/cfn2ts.ts#L43-L46
which makes it redundant to execute `cfn2ts --scope=scope` . 
3. Since the `gen` directive is now required in all cfn module, it was added to `cfnspec` so it will be added to every new module.
5. Added a `gen.sh` script in `scripts`, executing it will build `cfn2ts` and then execute `lerna gen`. This is useful if one wants to only get the `.generated` files without running a full build.

This PR originally included the changes require to split the monocdk build, these were removed from this PR to make it easier to review. The monocdk build related changes will be submitted in a different PR.


 
----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

build.sh

@@ -37,6 +37,11 @@ done
 export PATH=$(npm bin):$PATH
 export NODE_OPTIONS="--max-old-space-size=4096 ${NODE_OPTIONS:-}"
 
+if ! [ -x "$(command -v yarn)" ]; then
+  echo "yarn is not installed. Install it from here- https://yarnpkg.com/en/docs/install."
+  exit 1
+fi
+
 echo "============================================================================================="
 echo "installing..."
 yarn install --frozen-lockfile --network-timeout 1000000
@@ -65,11 +70,6 @@ rm -rf $BUILD_INDICATOR
 export MERKLE_BUILD_CACHE=$(mktemp -d)
 trap "rm -rf $MERKLE_BUILD_CACHE" EXIT
 
-if ! [ -x "$(command -v yarn)" ]; then
-  echo "yarn is not installed. Install it from here- https://yarnpkg.com/en/docs/install."
-  exit 1
-fi
-
 echo "============================================================================================="
 echo "building..."
 time lerna run $bail --stream $runtarget || fail

packages/@aws-cdk/alexa-ask/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "Alexa::ASK",

packages/@aws-cdk/aws-accessanalyzer/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "compat": "cdk-compat",
     "build+test": "npm run build && npm test",
-    "build+test+package": "npm run build+test && npm run package"
+    "build+test+package": "npm run build+test && npm run package",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AccessAnalyzer",

packages/@aws-cdk/aws-acmpca/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::ACMPCA",

packages/@aws-cdk/aws-amazonmq/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AmazonMQ",

packages/@aws-cdk/aws-amplify/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test": "npm run build && npm test",
     "build+test+package": "npm run build+test && npm run package",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Amplify",

packages/@aws-cdk/aws-apigateway/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::ApiGateway",

packages/@aws-cdk/aws-apigatewayv2/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "compat": "cdk-compat",
     "build+test": "npm run build && npm test",
-    "build+test+package": "npm run build+test && npm run package"
+    "build+test+package": "npm run build+test && npm run package",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::ApiGatewayV2",

packages/@aws-cdk/aws-appconfig/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AppConfig",

packages/@aws-cdk/aws-appflow/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AppFlow",

packages/@aws-cdk/aws-applicationautoscaling/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::ApplicationAutoScaling",

packages/@aws-cdk/aws-applicationinsights/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::ApplicationInsights",

packages/@aws-cdk/aws-appmesh/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AppMesh",

packages/@aws-cdk/aws-appstream/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AppStream",

packages/@aws-cdk/aws-appsync/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AppSync",

packages/@aws-cdk/aws-athena/package.json

@@ -56,7 +56,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "keywords": [
     "aws",

packages/@aws-cdk/aws-autoscaling/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AutoScaling",

packages/@aws-cdk/aws-autoscalingplans/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::AutoScalingPlans",

packages/@aws-cdk/aws-backup/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test": "npm run build && npm test",
     "build+test+package": "npm run build+test && npm run package",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Backup",

packages/@aws-cdk/aws-batch/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Batch",

packages/@aws-cdk/aws-budgets/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Budgets",

packages/@aws-cdk/aws-cassandra/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Cassandra",

packages/@aws-cdk/aws-ce/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CE",

packages/@aws-cdk/aws-certificatemanager/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CertificateManager",

packages/@aws-cdk/aws-chatbot/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Chatbot",

packages/@aws-cdk/aws-cloud9/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::Cloud9",

packages/@aws-cdk/aws-cloudformation/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CloudFormation"

packages/@aws-cdk/aws-cloudfront/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CloudFront",

packages/@aws-cdk/aws-cloudtrail/package.json

@@ -49,7 +49,8 @@
     "integ": "cdk-integ",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CloudTrail",

packages/@aws-cdk/aws-cloudwatch/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CloudWatch",

packages/@aws-cdk/aws-codeartifact/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeArtifact",

packages/@aws-cdk/aws-codebuild/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeBuild",

packages/@aws-cdk/aws-codecommit/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeCommit",

packages/@aws-cdk/aws-codedeploy/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeDeploy",

packages/@aws-cdk/aws-codeguruprofiler/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeGuruProfiler",

packages/@aws-cdk/aws-codegurureviewer/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeGuruReviewer",

packages/@aws-cdk/aws-codepipeline/package.json

@@ -49,7 +49,8 @@
     "cfn2ts": "cfn2ts",
     "build+test+package": "npm run build+test && npm run package",
     "build+test": "npm run build && npm test",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodePipeline",

packages/@aws-cdk/aws-codestar/package.json

@@ -50,7 +50,8 @@
     "cfn2ts": "cfn2ts",
     "build+test": "npm run build && npm test",
     "build+test+package": "npm run build+test && npm run package",
-    "compat": "cdk-compat"
+    "compat": "cdk-compat",
+    "gen": "cfn2ts"
   },
   "cdk-build": {
     "cloudformation": "AWS::CodeStar",