[Feature] Allow Creation of Recurring Calendar Events

[CommanderStorm]

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

In a calendar, there are two kinds of events:

• recurring
• once-off

Currently, we display both the recurring and once-off events, but only allow the creation of the once-off events

Describe the solution you'd like

Allow the creation of recurring events (weekly, biweekly, monthly, or semesterly).

Additional context

If someone wants to tackle this, we would love a contribution to this.
The lead for the Campus app is @jakobkoerber and I would like to enable you to implement this feature
⇒ feel free to ping either me or Jakob if you have any questions, are stuck, ...

[kordianbruck]

Unfortunately the API that I wrote is a bit fugly. So it might need some adaptations or we "hack around it" by just creating 10 individual events for example.

[jakobkoerber]

Unfortunately the API that I wrote is a bit fugly. So it might need some adaptations or we "hack around it" by just creating 10 individual events for example.

We should definitely adapt the API endpoints before sending potentially up to hundred requests at the same time 😅 or we really have to limit the functionality. The TUMonline frontend already supports daily or weekly repeating calendar entries