cannot change calendar as guest of an event

[jalhubb]

Describe the bug
Cannot change the calendar of an event you are invited to

To Reproduce
Steps to reproduce the behavior:

1. Be invited to an event
2. Accept the invitation
3. The event is noted in the first valid calendar
4. Trying to change the calendar of the event is not possible

Screenshots

Additional context

• It is also not possible to choose which target calendar the event from the invitation should be added to in the first place
• Message at the top of event editor not accurate

Test notes:

• The calendar of an accepted event can be changed

[sees7ern]

Have run into the same issue. It would be great to have the option to make such changes locally so that I can colour-code business-related invites.