Reject all daily events in import

[MizukiTemma]

Short description

This PR changes the event import functionality so no event with daily recurrence can be imported.

Proposed changes

• Check the frequency and raise error if it is daily

Side effects

• None?

Resolved issues

Fixes: #3431

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Pull Request Review Guidelines

[JoeyStk]

Thank you very much! The code runs as expected and didn't cause problems. I only have one concern / one thing we should think of.
I imported the test calendar from Nextcloud that we used to test the imports. In there we have one event that repeats every day and one that repeats every two days. Both failed to be imported. I take it that this is expected. I just want to double check with @osmers and/or @hauf-toni if this is really what we want :)

[osmers]

I can see the problem that this is not very transparent for municipalities bcs they cannot see the import option and which events failed). On the other hand, so far we have no municipality using the import function (I think)...
Is this an issue we can tackle later? As in, approve this now but open another issue on how to deal with these events to that they fit the new event design?

[MizukiTemma]

@osmers
Thank you for reply. An issue is opened for the thema #3443

[charludo]

Thank you! 🎉