Improved New Space Creation flow

### Your use case

#### What would you like to do?
Currently, when creating a public space in element desktop, it compels you to create 2-3 new rooms within the space with no apparent way NOT to do this. There's no skip or cancel. As a result of this, you can navigate away from the space creation flow and there are uncertain consequences for not completing the setup flow.

#### Why would you like to do it?
I would love for optional parts of space setup (such as creating a set of new rooms for it) to be obviously skippable.

#### How would you like to achieve it?
I would like there to be a skip option for creating new rooms within a newly created public space, because I do not want to create the rooms and am concerned that when halting the space setup early something has been missed or set up incorrectly.

### Have you considered any alternatives?

An alternative would be NOT compelling people to create rooms in a new public space. I assume this is desirable in some way, so I don't think element would get rid of it.

### Additional context

_No response_