Possibility to discover unjoined rooms from a space

[CactiChameleon9]

Is your feature request related to a problem? Please describe.
Would be nice to be able to see a list of rooms and subspaces that belong to a space (and the ability to join them from there)

Describe the solution you'd like
A page, maybe accessed through the hamburger menu, where you can see the space's information and rooms

Describe alternatives you've considered
Low priority list of all available rooms on the main room lists for the respective spaces