compositor: Add MetaDnD private function to initialize XDND
We need to set XdndAware and XdndProxy on the stage window if running a X11 compositor, this is not necessary on wayland.
Takes over gnome-shell code doing this initialization.
We need to set XdndAware and XdndProxy on the stage window if running a X11 compositor, this is not necessary on wayland.
Takes over gnome-shell code doing this initialization.