Calendar invitation time proposals

[ChristophWurst]

How to use GitHub

• Please use the 👍 reaction to show that you are interested into the same feature.
• Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
• Subscribe to receive notifications on status change and new comments.

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

As a calendar user, I …

Describe the solution you'd like

tbd

Describe alternatives you've considered

tbd

Additional context

This is related to nextcloud/calendar#5697.