Major changes in 49.alpha:
* Remove default calendar row from the Calendar Management dialog
* Various internal cleanups in the Week View
* Add a style checker and commit rules to CI
* Improve search error state in the weather settings entry
* Various CSS style cleanups and enhancements
* Fix the focus ring in the Notes section of the event editor dialog
* When dragging events over the Week view, the preview height matches the event
  duration now
* Make event widgets act more like buttons, which fixes focus handling and
  allows for activating using keyboard, and also add a focus ring
* Implement keyboard navigation in the Month view
* Add test coverage and static scan in CI
* Fix a major memory leak
* Redesign the main window to show the full calendar view, make the sidebar
  hideable, move navigation buttons to the bottom, and make the main window
  adaptative
* Port all UI files to Blueprint
* Make event widgets properly accessible, and report their accessibility states
  correctly. This makes them readable by assistive technologies like screen
  readers.
* Fix accessibility and keyboard navigation of calendar toggle rows, the date
  chooser widget, and other UI elements.
* Port to Adwaita shortcuts dialog
* Updated translations