Support cursor-shape protocol #2859
Description
GTK4 doesn't load themed cursors anymore and relies on the cursor-shape protocol instead since 4.19. It means that currently all the GTK4 applications use wrong cursors (the gdk's built-in ones) and AFAIK the only way to fix this without Wayfire supporting the protocol is to rebuild GTK with custom cursors.
Wlroots and Sway do support the protocol, so I hope this should not be too hard.