Rework "Room page" to show 4/8/12 entities

[tpanajott]

Rework "Room page" to show a page of 4 entities if there are 4 or less entities registered in the room. If there are > 4 and <= 8 show a page with 8 entities on the page. If there are > 8 and <= 12 then show a page with 12 entities. If there are > 12 entities in the room, show a page with 8 entities and add buttons to toggle between different pages of entities for that room.