135c9194cd
According to the GNOME 40 mockups, add a box-shadow to the workspace background. For this to work, we also need a background-color (St limitations), and to make sure that background-color doesn't bleed over the rounded corners of the wallpaper, we also need to tell St to use a border-radius and clip the background-color painting using a rounded path. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1651>