gcal_util_
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/842>
Fallout from my changes to the previous commit.
Move the AdwActionRow for the event organizer into its own widget. In preparation for further widget customization. Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/671>