This is a GListModel implementation that is specific to
GcalEvents. Events are stored in a GSequence in order of
date.
Add a couple of tests exercising additions and removals.
WIP: add more tests
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/742>
Add a wrapper for the ECalComponentOrganizer. An instance of this type
is kept as part of the GcalEvent structure.
The GcalEventOrganizer is just a "proxy" to the ECalComponentAttendee
and its purpose is to unclutter the GcalEvent interface and provide a
bindable base for a UI widget.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/671>