Turn dataset_query into structured data in search results (#17690)

* Turn dataset_query into structured data in search results

* sort scoring test ns

* Fixup tests

we are no longer returning string results. The cards in the test have
empty queries, which the model turns into {} but normalization removes
empty clauses and returns nil. The tests would be too annoying to hook
this up to work properly and this functionality is tested in other
places.

* Unskip repro for #15959

* Update repro test

Co-authored-by: Anton Kulyk <kuliks.anton@gmail.com>