This CL migrates the `frontend_server_client` package into the Dart SDK
repository.
Key Changes:
- Migration: Moved source code and tests into `pkg/frontend_server_client`.
- Monorepo Compliance: Updated the pubspec to align with the SDK pub workspace setup.
- Linting: Adopts `package:dart_flutter_team_lints` for analysis options and fixes associated linting errors.
- Path Resolution: Resolved package configuration and script path issues encountered in local and CI environments; see the [Workspace Tests Fixes](https://docs.google.com/document/d/1UdiRqP19qYgj-ItxDfqXSdUU6CGimiyK3BmdvjtTEyw/edit?pli=1&tab=t.0#heading=h.xfm1ezicaoik) in the design doc for implementation details.
Testing:
- All tests passing locally.
- CI try bots are green.
Design Doc: http://goto.google.com/migrating-webdev
Cq-Include-Trybots: luci.dart.try:pkg-win-release-try,pkg-win-release-arm64-try,pkg-mac-release-try,pkg-mac-release-arm64-try,pkg-linux-release-try,pkg-linux-release-arm64-try,pkg-linux-debug-try
Change-Id: Id44a701107d626df5fcd21d724980243981c7958
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/461200
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Jessy Yameogo <yjessy@google.com>
Jonas Finnemann Jensen