The cursor texture, scale and position is captured separately and
overlaid on top of the preview, and on top of the final screenshot
image. This allows toggling it on and off post-factum.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1954>
UIWindowSelectorLayout is a stripped-down subclass of WorkspaceLayout
(we don't have to deal with windows disappearing or appearing or
changing size). UIWindowSelectorWindow is a heavily stripped-down
version of WindowPreview. UIWindowSelector is analogous to the Workspace
class.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1954>
