Not only hook the ResizeWindow method of the screen (which really is
MoveAndResize) but also hook the MoveWindow method for checking if we
need to setup a viewport for resolution change emulation.

Our resolution change emulation check if the windows origin matches
the monitors origin and the windows origin can also be changed by just
a move without being resized.

Also checking on a move becomes esp. important when we move to checking
on changes to the top-level non-window-manager client (X11)Window instead
of on changes to the xwl_window later on in this patch series.

Acked-by: Olivier Fourdan <ofourdan@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>