
ThumbnailsBox currently allocates each workspace thumbnail using their porthole size, and scales them down using scale-x and scale-y. This is slightly problematic since it doesn't allow for properly styling these thumbnails through CSS. Rework ThumbnailsBox to allocate workspace thumbnails at their actual sizes, and scale down the '_contents' actor inside WorkspaceThumbnail. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1593>