R1:72f149bf399a

Require rows passed to "loadAllFromArray()" have unique keys

Summary:
See PHI1809, which identified a bug in Project search where queries with a large number of slugs could paginate improperly.

This change detects problems in this category: cases where multiple rows with the same ID are passed to "loadAllFromArray()". It's likely that all cases it detects are cases where a GROUP BY is missing.

Since this might have some false positives or detect some things which aren't fundamentally problematic, I'm…