Add '16 mouse buttons' feature to InputDevice::toWaylandButton
Add '16 mouse buttons' feature to InputDevice::toWaylandButton

Task-number: QTBUG-22759

Change-Id: Id886a61a98e07bfeb4a18ef57905d6b7293ca0c8
Reviewed-by: Samuel Rødal <99126055f8d73e4355b075213322026fa8c060bd@nokia.com>

locusf/qtwayland-1,locusf/qtwayland-1,Tofee/qtwayland,ntanibata/qtwayland,ntanibata/qtwayland,locusf/qtwayland-1,Tofee/qtwayland,ntanibata/qtwayland,Tofee/qtwayland,locusf/qtwayland-1