R1:00b1c4190c41

Correct some straggling Ferret/Cursor interactions

Summary:
See PHI1182. Ref T13266. The recent fixes didn't quite cover the case where you have a query, but order by something other than relevance, and page forward.

Refine the tests around building/selecting these columns and paging values a little bit to be more specific about what they care about.

Test Plan:
Executed queries, then went to "Next Page", for:

- query text, non-relevance order.
- query text, relevance order.
- no query text, non…