Add support for inertial scrolling

[Porkepix]

This is probably a limitation of the toolkit and can't be implemented by you unless toolkit add it, but in case something could be done: inertial scrolling from trackpad is pretty common nowadays and would be a nice comfort addition.

[AHSauge]

I don't have a laptop or touch screen to test this with right now, but it should be fairly easy to add using https://doc.qt.io/qt-6/qscroller.html

Specifically, I believe this is all that needs to happen to widgets we want this effect on

QWidget *w = ...;
QScroller::grabGesture(w, QScroller::TouchGesture);