Spaces should have identifiers for public vs private spaces

### Your use case

#### What would you like to do?

I'd like to be able to visually distinguish my personal spaces from the public spaces I'm a part of

#### Why would you like to do it?

When managing a more than a few spaces, it's helpful to be able to tell which are mine and which are public.

#### How would you like to achieve it?

Rooms currently show a small "world" icon in the bottom-right corner when they are public, eg:


Private rooms do not have this. Spaces do not appear to do this - none of my spaces, public or otherwise, have such an indicator. Would it be possible for spaces to use the same "public" indicator as rooms?

### Have you considered any alternatives?

I can't think of anything simpler, and I don't believe spaces has any other way to indicate visibility at the moment. Happy to be corrected of course.

### Additional context

Clearly a cosmetic issue, but one that would help when dealing with more than a handful of spaces - as well as make spaces have a consistent UI alongside rooms.