The `verifyPlaceholdersIntegrity` check in the compliance tests was basically a noop, because it was returning false inside a `forEach` callback. Fixing it revealed that it had fallen out of date, because one of the regexes it uses was incorrect. The problem is that it assumed the placeholder keys would always be string literals, however it's possible that they're identifiers. These changes resolve the issue by not looking at the keys at all since we don't do anything with them.
PR Close#51751
Currently internally Angular has some customized tsconfig files, because we don't align with the tsconfig of the rest of g3. These changes enable `noImplicitReturns` and `noPropertyAccessFromIndexSignature` to align better with the internal config.
PR Close#51728
This commit provides the machinery for the new file-based compliance test
approach for i18n tests, and migrates the i18n tests to this new format.
PR Close#39661