wayland: Add support for wayland-protocols primary selection protocol

This protocol was added some time ago. Supporting it fell through the
cracks. Add new data device/source/offer implementations for it,
interoperation between primary selection protocols (and X11 primary
selection for that matter) comes for free.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/943

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1255

(cherry picked from commit 2becb3dd)