Send all participants to backend when invited users of a room change.
Send all participants to backend when invited users of a room change.

All existing participants need to update the room, so the signaling server
needs to know who to notify.

Signed-off-by: Joachim Bauch <f7be0a2a0fb4eba859c8fa4289260059dc564a0d@struktur.de>

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed