Is your feature request related to a problem? Please describe.

If you create a calendar it's currently always considered for free/busy scheduling. There are cases where you don't want this, e.g. for a calendar that is supposed to be used for a group, then the owner (the person who shared) shouldn't be seen as blocked for the shared events. But also sometimes you might create a calendar for something that isn't an actual event where you are busy, and you don't want to set your availability to free for every event you create in there.

Describe the solution you'd like

Offer users a checkbox on the calendar action menu where they can toggle the free/busy transparency.

Describe alternatives you've considered

N/a

Additional context

• The standardized property https://icalendar.org/CalDAV-Scheduling-RFC-6638/9-1-caldav-schedule-calendar-transp-property.html
• Handling in Sabre https://github.com/sabre-io/dav/blob/c1afdc77a95efea6ee40c03c45f57c3c0c80ec22/lib/CalDAV/Schedule/Plugin.php#L890-L894