Create flutter-web application

[ltackmann]

The web application created by flutter create also includes support for iOS and Android which can be hard to remove if one only wants a pure web application. It would be usefull if stagehand could create a pure flutter web application without dependencies on iOS and Android for those of us who want to use flutter for web only programming.

[domesticmouse]

The Flutter web template has been removed.

/cc @kevmoo can I have admin access back so I can close issues? kthnxbi