Cache surfaces that are opened via shm_open inbetween updates.
-Send configure event when a window is moved and no client
Handle implicit grabs when in broadway-server.c
-Rewrite events (per-client serials, etc)
keyboard focus handling
Add resize handling to js WM
-Make canvas/title non-selectable in browser
-Handle browser window size changes
+Support window titles
_gdk_broadway_server_has_client is always FALSE, so resize don't work
Send reset events on client disconnect (button up, normal state. Maybe grab state reset?)
rgba suport