Major changes in 51.alpha:
* Completely rework the internals of GNOME Calendar to be based on GListModel.
  Notably, GcalTimeline and GcalTimelineSubscriber all operate on GListModels,
  and so do the views (week, month, and agenda).
* A number of performance improvements and rendering optimizations to the Month
  view and to event widgets
* Vastly reduce amount of data exchanged by Calendar and Evolution Data Server
* Support the maps URI for opening locations
* Use a better month name formatting in various places
* Make the Week view work with the high-contrast setting
* Cleanup and improve the event editor dialog
* Adapt CSS to the latest libadwaita and GTK standards
* Don't change the refresh interval during startup. This avoids changing values
  set by the user in Evolution.
* Explicitly state when app is not contained inside Flatpak in the About dialog
* Cleanup the Flatpak manifest
* Add support for Teams links
* Visual improvements to the Notes section of the event editor dialog
* Updated translations