Search integration tests

WIP for adding more integration tests around search.

- [x] with restricted attributes
- [x] with filter string
- [x] with filter object
- [ ] with size limit (failing test)
- [ ] attributes_only
- [ ] deref (don't know how to test this)
- [ ] scope (needs additional fixtures)

cc @mtodd @schaary 
I moved these down to the filter tests.