So far the key handler in the InternalWindowEventFilter used the
PointerInputRedirection's internal window. This had the result that
key events were only delivered to an internal window if the window
was under the cursor.
This change tries sending the event to the latest created and visible
window. Thus e.g. with nested context menus it goes to the current
sub menu as expected. The return value of sendEvent is used to filter
out the event.
The test creates a QRasterWindow which through KWin's internal QPA
is considered an internal window. In the test methods we simulate
various pointer events (enter/leave, press/release, wheel).
