When searching for events, users are typically interested in finding the
event rather than seeing a repetitive list of every occurrence instance.
By configuring the search timelines with "expand-recurrences" set to FALSE,
recurring events are loaded as their single master component instead of
expanding all individual occurrences.
Additionally:
- Update GcalSearchHitEvent subtitle to display "Recurring" (e.g. "Tomorrow • Recurring"
or "Recurring") when the event has a recurrence rule.
- Safeguard gcal_event_format_date() when running without a default GApplication.
Fixes: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/991
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/808>