Upgrade most samples to Flutter 3.35.2

[brianegan]

• Use fvm to run flutter commands
• Uprade most samples to Flutter version 3.35.2. I had to remove some for the sake of time, as the libraries have changed dramatically or been abondanded. Would be happy to restore any I shouldn't have!
• Moved all CI workflows to github
• Migrate from package flutter_driver to package integration_test
• Removed Firebase examples. Cluttered the samples a bit.
• All samples now have wasm web demos

[codecov]

Codecov Report

❌ Patch coverage is 82.71605% with 42 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@41a033f). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
bloc_flutter/lib/screens/add_edit_screen.dart	0.00%	14 Missing ⚠️
bloc_flutter/lib/widgets/todo_list.dart	18.75%	13 Missing ⚠️
bloc_flutter/lib/screens/detail_screen.dart	0.00%	10 Missing ⚠️
bloc_flutter/lib/screens/home_screen.dart	92.30%	1 Missing ⚠️
bloc_flutter/lib/widgets/extra_actions_button.dart	50.00%	1 Missing ⚠️
bloc_library/lib/bloc_library_keys.dart	66.66%	1 Missing ⚠️
.../lib/blocs/filtered_todos/filtered_todos_bloc.dart	95.23%	1 Missing ⚠️
bloc_library/lib/blocs/stats/stats_bloc.dart	92.85%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #215   +/-   ##
=======================================
  Coverage        ?   68.39%           
=======================================
  Files           ?      135           
  Lines           ?     3420           
  Branches        ?        0           
=======================================
  Hits            ?     2339           
  Misses          ?     1081           
  Partials        ?        0           

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