Adding support for AdwBanner
Hi, It looks like AdwBanner, which was added in 1.3 according to its documentation, is missing from the crate despite commit dab619d5 which adds bindings for this version. I'm new to Gtk so maybe there is a good reason for not including it which I'm not aware of, otherwise this looks like a great widget for modern UIs and I would be grateful if I was able to use it! Thanks