create meetings with easy URLs

[ramack]

When creating a new meeting with the nextcloud-jitsi app, the meeting URL is

https://nextcloud.my.url/index.php/apps/jitsi/rooms/XXXXXXXXXX-XXXX-XXX-XXXX-XXXXXXXXXXX/test

especially because it is not possible to invite new users right now it would be much nicer to use the meeting URL https://meet.my.url/test

for the meeting called test, then we could easily mix the use of "nextcloud users" and guests via the classical jitsi address.

[rasos]

In our fork of the Jitsi app we have now also integrated adding a room to a new event (longer than a minimum duration, default = 15 min). The room name is derived from the meeting topic, you can configure a prefix for the room name and we add a hash to make it unique. Check out https://apps.nextcloud.com/apps/fairmeeting