Kibana APIs - Spaces URL "prefix"

[kobelb]

We should document the approach in which the space URL prefix is used with the existing Kibana APIs. For example, if you wanted to use the saved object APIs for a specific space, you'd use http://localhost:5601/s/foo/api/saved_objects/ instead of http://localhost:5601/api/saved_objects/.

[elasticmachine]

Pinging @elastic/kibana-security

[KOTungseth]

@kobelb could you push the changes for this? I can push them too, but I would need some more information.

[legrego]

I think @mellieA had started working on this, but I don't know the current status. I'm happy to help drive this too.

[mellieA]

Updated all of the saved_object APIs to include /s/<space_id> in #38788 and #47627 so I'll close this one out.