Fix status in orphan feature

No PT/Jira story

- fix incorrect references to OrphanStatus/OrphanSponsorshipStatus in orphan.feature
- remove references to 'Sponsored'/'Unsponsored' as these belong to OrphanSponsorshipStatus and are never set manually
- add tests for fields in index view
As long as ActiveAdmin keeps playing by the same rules, these should be no more brittle than saying `expect(model.attribute).to eq value` in specs, both in terms of the CSS & the expected value. We just have to keep specifying both the attributes and the expected values carefully and fully.

How could the CSS rules be relaxed here?

My concern with `have_content` is that e.g. 'Active' and 'Not Active' or similar would both match on `have_content` but not on `eq`.