54884 [flutter_tools] Provide global options with subcommand help text (cla: yes, tool)

54909 [flutter_tools] fix multiple defines in flutter tooling, web (cla: yes, team, tool)

54912 Move doctor into globals (cla: yes, team, tool)

54916 Convert expression evaluation exceptions to errors (cla: yes, team, tool, waiting for tree to go green)

54918 [flutter_tools] ensure EventPrinter handles a null parent (cla: yes, tool, waiting for tree to go green)

54920 [flutter_tools] remove Isolate implementations of vm_service methods (cla: yes, tool)

54923 [flutter_tools] default tree-shake-icons to enabled and improve performance (cla: yes, tool)