Implement window hiding in the WaylandClient class
This change upstreams window hiding functionality from the XdgSurfaceClient class to the WaylandClient class in order to reduce the amount of duplicated code in new wayland client sub-classes.
This change upstreams window hiding functionality from the XdgSurfaceClient class to the WaylandClient class in order to reduce the amount of duplicated code in new wayland client sub-classes.