Handle locked rooms that you are not in

[konklone]

On RoomList, indicate if a room is locked. Don't grey it out, because admins can enter locked rooms.

In RoomView, handle the response code (whatever it is) from the "recent" endpoint, and show a message saying it's locked. The Transcript tab should function as normal. Depend on the response code, not whether the room's locked field is set to true, because admins can enter locked rooms.