The caribou daemon only gives us focus tracking, which is almost 1:1 with
our own FocusCaretTracker implementation. This means we can entirely
replace the Caribou daemon inside gnome-shell, reducing the Caribou
dependency to just libcaribou, and more specifically the
CaribouKeyboardModel we pull the keyboard models from.
As we still need underneath a CaribouDisplayAdapter to drive the keyboard,
reuse the wayland one, which has been renamed to make it look generic, plus
it will use the virtual input device API from mutter/clutter.
https://bugzilla.gnome.org/show_bug.cgi?id=777342
aecd1c126a