Commit 8d3e05305 ("window: Force update monitor on hot plugs") added the
flag `META_WINDOW_UPDATE_MONITOR_FLAGS_FORCE` passed to
`update_monitor()` from `update_for_monitors_changed()`.
However, `update_for_monitors_changed()` may choose to call another code
path to `move_between_rects()` and `meta_window_move_resize_internal()`
eventually.
As `meta_window_move_resize_internal()` does not use the "force" flag,
we may still end up in case where the window->monitor is left unchanged.
To avoid that problem, add a new `MetaMoveResizeFlags` that
`update_for_monitors_changed()` can use to force the monitor update from
`meta_window_move_resize_internal()`.
Fixes: 8d3e05305 ("window: Force update monitor on hot plugs")
Closes: https://gitlab.gnome.org/GNOME/mutter/issues/189
e9d41e0898