shell: Add square and circle annotations

Adds the interior color property of the circle and square annotations
to the properties dialog.

Extends fix for #204
4 jobs for wip/gpoo/204-annot-square-and-circle in 7 minutes and 41 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #791917
flatpak
flatpak

00:07:41

manual #791914
allowed to fail manual
master
passed #791915
meson

00:01:00

manual #791916
allowed to fail manual
meson-gtk-doc