49454 [infra] reduce cirrus task dependencies (cla: yes, team, waiting for tree to go green)

49455 Make local-engine an input property (cla: yes, tool, waiting for tree to go green)

49458 Move Xcode context fetch to global.dart (cla: yes, team, tool, waiting for tree to go green)

49459 [flutter_tools] handle plugins for entrypoints outside of lib (cla: yes, tool, waiting for tree to go green)

49460 Initial web benchmark harness and 3 benchmarks (cla: yes, team)

49462 Replace FlutterVersion.instance with FlutterVersion context fetch in global.dart (cla: yes, team, tool, waiting for tree to go green)

49463 Inject platform into build ios-framework command (cla: yes, team, tool)