Revert "[web] Migrate framework to fully use package:web" (#129400)

Reverts flutter/flutter#128901

context: ([cl/542712088](https://critique.corp.google.com/542712088) , [b/288495136](https://b.corp.google.com/288495136))
https://dart.googlesource.com/external/github.com/flutter/flutter/+/363e2f7e0b878cc6f211f02afb1cffa0513bb6c2