This builds on top of the existing UI/code, while adding a few improvements and
behavioral changes:
- The popover displays the changes-prevent icon when the even is read-only.
- Each section is properly separated with `GtkSeparator`s, with equal amount of
top and bottom margins.
- Location and Meetings section are mutually exclusive; only one is shown.
- When an event has no event note, the popover will always display that there's no
description.
- `GcalMeetingRow` has been ported to `GtkListBoxRow`.
- The action button adapts its icon and tooltip text depending on the event
permission.
GcalEventPopover gives a preview of the event, and handy access
to the event description and information. It also allows easily
joining meetings if any one if available.
The list of supported meeting URLs is small now, but I hope
more people will contribute as we go.
It is also possible to edit the event through an edit button.
Jamie Gravendeel