Intended to be used to pass state from screen cast clients down the
line. The first use case will be a boolean whether a screen cast is a
plain recording or not, e.g. letting the Shell decide whether to use a
red dot as the icon, or the generic "sharing" symbol.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1377
Make the RecordWindow method also understand the 'cursor-mode' property.
For 'embedded' the cursor is drawn onto the pixel buffer using cairo,
otherwise it works similarly to how RecordMonitor deals with it.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/413
