Since the GtkListBox is bound to the calendars GListModel, and since the
GListModel is already sorted, there is no longer a need for sorting the
rows by name.
When enabling or disabling a calendar through the GcalCalendarButton
popover, the user loses the ability to click right after. This bug was
caused by the update mechanism, triggered by the calendar-changed signal,
which would delete then create a brand new GtkWidget for the row.
To fix this, I replaced the manual signal-based create, update and
remove mechanisms with a binding between the GtkListBox and the calendar
GListModel.
GtkSpinner queues relayouts even when the stack is not displaying
it, and this causes excessive redrawing. This button design looks
obsolete and should eventually be reworked, but for now, let's
just stop spinning when the spinner is invisible.
Closes https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/971
Enzo MAROS