feature: add mouse scroll wheel event

[hololeo]

Add mouse wheel support for web/desktop.

Possibly relevant documents and links:

https://www.youtube.com/watch?v=KKDNNXEPhgc https://api.flutter.dev/flutter/gestures/PointerScrollEvent-class.html https://stackoverflow.com/questions/64985580/flutter-web-gesturedetector-detect-mouse-wheel-events https://medium.com/nerd-for-tech/flutter-handling-mouse-events-241108731537