Allow specifying hostname for Hapi servers. (#12)

And specify it as "localhost" for the servers that are started by the integration tests.

Some of the integration tests were failing for me because:
- My laptop is configured with both IPv4 and IPv6 for localhost (and non-localhost, too, but that's not relevant here).
- Hapi binds to 0.0.0.0 by default ([API docs](https://hapi.dev/api/?v=20.2.2#-serveroptionsaddress), [code reference](https://github.com/hapijs/hapi/blob/b8ba0adc7c3255995cb56a9a740c4f9750b80e6b/lib/core.js#L339)).
- That's an IPv4 address so the server will only accept connections over IPv4 and not IPv6.
- Our integration test config specifies `localhost` when creating the clients for connecting to these servers.
- `localhost` can resolve to an IPv6 address.
- Node before v17 sorted IP addresses from the name resolver so IPv4 addresses were first but Node v17 and newer returns them in the order returned by the resolver ([GitHub comment](nodejs/node#40537 (comment)), [relevant PR](nodejs/node#39987), it's the first "Other Notable Changes" in [the v17.0.0 release notes](https://nodejs.org/en/blog/release/v17.0.0/#other-notable-changes)). Apparently on my laptop an IPv6 address is returned before an IPv4 address.

Alternatively I could have changed the test config so clients connect to 127.0.0.1. I like this change because:
- It's nice to allow users to specify the address to bind to anyway.
- Now the test servers will bind to localhost instead of 0.0.0.0 and it's nice to avoid accepting outside connections when possible.

packages/thrift-integration/src/calculator-strict-unions.ts

@@ -184,6 +184,7 @@ export async function createServer(
    * Creates Hapi server with thrift endpoint.
    */
   const server: Hapi.Server = await createThriftServer({
+    address: HAPI_CALC_SERVER_STRICT_CONFIG.hostName,
     port: HAPI_CALC_SERVER_STRICT_CONFIG.port,
     path: HAPI_CALC_SERVER_STRICT_CONFIG.path,
     thriftOptions: {

packages/thrift-integration/src/hapi-add-service.ts

@@ -33,6 +33,7 @@ export async function createServer(sampleRate = 0): Promise<Hapi.Server> {
    * Creates Hapi server with thrift endpoint.
    */
   const server: Hapi.Server = await createThriftServer({
+    address: ADD_SERVER_CONFIG.hostName,
     port: ADD_SERVER_CONFIG.port,
     path: ADD_SERVER_CONFIG.path,
     thriftOptions: {

packages/thrift-integration/src/hapi-calculator-service.ts

@@ -169,6 +169,7 @@ export async function createServer(
    * Creates Hapi server with thrift endpoint.
    */
   const server: Hapi.Server = await createThriftServer({
+    address: HAPI_CALC_SERVER_CONFIG.hostName,
     port: HAPI_CALC_SERVER_CONFIG.port,
     path: HAPI_CALC_SERVER_CONFIG.path,
     thriftOptions: {

packages/thrift-server-hapi/src/main/index.ts

@@ -18,6 +18,7 @@ export function createThriftServer<TProcessor extends IThriftProcessor<Hapi.Requ
   options: ICreateHapiServerOptions<TProcessor>
 ): Promise<Hapi.Server> {
   const server = new Hapi.Server({
+    address: options.address,
     port: options.port,
     debug: { request: ['error'] },
   })

packages/thrift-server-hapi/src/main/types.ts

@@ -37,7 +37,8 @@ export interface IHapiPluginOptions<TProcessor extends IThriftProcessor<Hapi.Req
 
 export interface ICreateHapiServerOptions<TProcessor extends IThriftProcessor<Hapi.Request>>
   extends IHapiPluginOptions<TProcessor> {
-  port: number
+  address?: Hapi.ServerOptions['address']
+  port?: Hapi.ServerOptions['port']
 }
 
 export type ThriftHapiPlugin = Hapi.Plugin<void>