Qt5X11Extras (QX11Info) was added in
762983b5d853ba8444c4efee450ea872b294060e, but it doesn't seem to
actually be used. Qt6 doesn't yet ship X11Extras, so let's remove it.
Ignore wheelEvent using subclass
slider,spinbox,combobox with eventhandlers:
wheelEvent - ignore if widget is not focused,
leaveEvent - clear focus when mouse leaves event.
Use these new subclass widgets in properties
to ignore wheelEvent when scrolling.
