Optionally hit postgres instead of fdbsql
Helpful debug log

This allows you to quickly start debugging in the failing
test query
expected is empty if right hand is all null
drop tables at startup when hitting postgres
Pass query index down to in

for even easier debugging
Handle null correctly

oh so many weird edge cases
Always sort expected & actual

because sometimes the results aren't in the same order
A bit of refactoring for !useIn && insideHasNull
Extracted some helper methods
pass queryIndex to exists test
Include query index in error message
Compare to constant not literal
Postgres puts nulls at the end
It's called postgresql
Added comment about running against postgresql
Add a couple new classes for managing committing scans consistently.
Propagate those around in place of various ad-hoc variations.
Adjust constructor a little to make testing easier.
Add the minimal IT for that.
Need to track current and total counts separately.