79580 [flutter_tools] split cache into API and implementation (cla: yes, tool)

79583 Restore support for the –local-engine flag in devicelab/bin/run.dart (cla: yes, team, waiting for tree to go green)

79587 Migrate fingerprint to null safety (a: null-safety, cla: yes, team, tool)

79590 Revert “Don’t call onChanged callbacks when formatter rejects the change & handle text input formatter exceptions. (#78707)” (cla: yes, framework, waiting for tree to go green)

79603 [flutter_tools] split features into 2 libraries, migrate to null safety (cla: yes, tool)

79608 Remove “unnecessary” imports in test/widgets (cla: yes, framework, tool, waiting for tree to go green)