Add an NPM workspace and use prettier for non-rust source files

[kjvalencik]

Tip for reviewing: Review the individual commits instead of the PR. Ignore the "Prettier!" commit where files are formatted in mass; there are no code changes in that commit.

This is a very large diff because of prettier and lock files, but the actual changes are all in config files.

• Make the root of the project an NPM workspace, creating a root package-lock.json
• Move all NPM packages in the project to the workspace; this deletes their individual lockfile
• Moved NPM tests from src/lib.rs executors into the workspace tests
• Updated CI to call npm test instead of cargo test
• Bumped package versions to unify the workspace and eliminate audit failures
• Disabled lib checks in tsc to fix compilation; we can revert this after spectron is removed
• Ran prettier on the entire project for all js, ts, json, and yml files (excluding generated)
• Added a prettier check to our CI lint job

@dherman I used the default prettier configuration. If there's something about the formatting you don't like, let me know and we can tweak it. I prefer tabs, but we were already using two-spaces.

As a nice benefit, it also fixes the legacy backend on newer NPM versions.

[dherman]

Lots of great cleanup! I'm excited to use workspaces and get rid of the recursive cargo test.

One suggestion in the comments, and then I'd suggest maybe just adding some brief docs to the main README on how to run the Neon tests (npm test in general, npm test --workspace=test/foo for individual subtests).