refactor: rewrite e2e testing

[jtdLab]

1. Refactor test setup to not use setUp and tearDown to switch cwd and projectName.
2. Consider running android, ios and mobile slow e2e tests on [Firebase Testlab] or make them faster in other way (https://firebase.google.com/docs/test-lab).
   • https://github.com/flutter/flutter/tree/main/packages/integration_test
   • https://docs.flutter.dev/testing/integration-tests

[jtdLab]

2. wont be implemented for now

[jtdLab]

1. added with 3c50167c3436aab6f62759b96d0b8430ae09639d