Started handling messages from background isolates. by @gaaclarke in https://github.com/flutter/flutter/pull/109005

Revert “Started handling messages from background isolates.” by @gaaclarke in https://github.com/flutter/flutter/pull/111318

Create class MemoryAllocations. by @polina-c in https://github.com/flutter/flutter/pull/110230

[web] skip more perspective text tests by @yjbanov in https://github.com/flutter/flutter/pull/111402

Reland: Started handling messages from background isolates. by @gaaclarke in https://github.com/flutter/flutter/pull/111320

[framework] work around to load self packages from packages/ by @jonahwilliams in https://github.com/flutter/flutter/pull/111350