We are about to make the tool a user-visible application, so we need an icon. Add one (plus its symbolic variant). https://gitlab.gnome.org/GNOME/gnome-shell/issues/1968
This is what most GNOME modules now use instead of a shell script, which makes sense given that the build system itself is written in python. This particular copy comes from nautilus ... https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/920