Fix status in orphan feature

~~No PT/Jira story~~ JIRA story https://osraav.atlassian.net/browse/OSRA-160

- 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

## JIRA
OSRA-160 #Code-Review
@PurityControl, @motasem-salem: In the (current) absence of fixtures, what do you think about extracting all these calls to factories for reference models into a single `Given all seeded db records exists` (please suggest a better name!). This step would essentially equal fixtures in that it would create all the data currently in our seeds.rb. Then, it can be included in `Background` in each feature and we won't have to worry about creating all the relevant associations each time.