favorits: Work around broken app_id in most GTK+3 apps.
See https://gitlab.gnome.org/GNOME/gtk/merge_requests/284 for details.
This at least fixes the icons for the GNOME core apps we're using until they call g_set_prgname() correctly or switch to GTK+4.
Signed-off-by: Guido Günther guido.gunther@puri.sm