Migrate: Calendar events

Add some calendar events in Moodle (user, group, site, ...). Go to calendar events in the app and check that you can see the events. Check that infinite scroll and pull to refresh work as expected. Change the notification time and check that the notification is triggered when it should. Register more than one site on your app and check that the app triggers notifications from different sites. Click on a notification from your site (currently logged in) and check that you're redirected to the event page. Click on a notification from another site and check that you're re-logged on the right site and redirected to the event page.