* Starts using the `--source` flag to compile the dart registrant.
* updated general.shard tests
* Fixed the resident compiler flow
* added integration test
* made the integration test self contained
* renamed generated_main to dart_plugin_registrant
* cleaned up for review
* added task runner for ci
* added bringup and TESTOWNERS
* updated failure message
Building an application for a desktop platform that transitively included any Dart-based plugins (such as path_provider) broke `flutter test`, because its compilation was overriding the provided main (in this case, the test main) with `generated_main.dart` if it was present. This PR:
- Changes the `flutter test` compilation path to update `generated_main.dart`, so that the tests will work, and will include any registered Dart plugins.
- Makes using `generated_main.dart` during recompile opt-in, to try to reduce the chance of a similar bug happening with other codepaths in the future.
Fixes https://github.com/flutter/flutter/issues/88794
