Link and interactive widgets for open meetings

[ChristophWurst]

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

As a Nextcloud Calendar user I want to create an event for a meeting and allow people to join the meeting freely. For example, I offer a workshop for colleagues.

Describe the solution you'd like

I create an event and click Open meeting (or better wording) that give me a link. I share that link in a Talk room or Text document. Others can click it to add themselves as accepted attendee.

In addition, this could be done as nextcloud/server#42550 with an interactive button. The button can be clicked in place and it's not necessary to open a calendar page to add oneself as attendee.

Describe alternatives you've considered

No response

Additional context

No response