qml: fix wheeling on playback speed control does not work on Wayland with certain mouse types

By default WheelHandler only accepts mouse (unlike other handlers where all devices are accepted by default), and it also does not make use of synthesized mouse events. We can accept all devices here, I don't see why we should limit the accepted devices here.

Currently on Wayland certain mouse types are not reported as "mouse", this is a problem for the wheel functionality of the playback speed control. Accepting all devices fixes this issue.

Request review @chub.