Add infrastructure and tests for evaluation with frontend_server (#902)

- Create new non-public package:frontend_server_common
  - logic is a fork of the Frontend Server compiler logic from Flutter
  - Long term this package will contain a shared set of logic for use from package:dwds, package:webdev and package:flutter_tools
- Add new tests to stress the Frontend Server compiler
  - Tag those tests as `frontend-server` and skip for now
  - Waiting for https://dart-review.googlesource.com/c/sdk/+/138010 to land in the dev channel
- Update `modules.dart` to handle both compilers (Frontend Server, package:build*)
  - As this directly impacts breakpoint logic, split these tests out and make them explicit
40 files changed