Make /rooms API endpoint not require user

[MaxOhn]

Similar to #11521

As far as I can tell, the only reason the /rooms endpoint currently requires a user is so that Room::search is able to determine whether the user has participated or owns the room if the corresponding mode is specified in the query.

Perhaps these modes could just be rendered useless or result in an error if the request is performed without authenticated user?

And just to mention my use case, I'd love for a way to fetch daily challenges' room ids without an authentication.