Only one of them may be active at a time, so track the type of active gesture so it can get properly cancelled. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2640>
We will want to trigger this from multiple places for cancellation. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2640>
Update the pointer gestures protocol to version 3 and implement the new hold gesture. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1830>