InputRedirection forwards pointer events (currently motion, press and
release) through the EffectsHandlerImpl for the case that an effect has
intercepted pointer events.
If the KWin operation mode is not X11 only, the window for intercepting
the mouse events is no longer created.
So far this new class is not yet doing much. The WaylandBackend forwards
the received pointer events to this InputRedirection class. From there
signals are emitted to inform internal areas about the changes first.
The events are currently forwarded to X through the xtest extension. This
will be removed in future. Input will be forwarded directly to the
surface which wants it (no matter whether X11 or Wayland).