Repair database wrt indexes / unique constraints * recreate indexes dropped by 3.23 migration (but it's still unclear why) * attempt drop remaining extra indexes (there may be a bunch of these on old instances) * warn about missing expected indexes Closes #16666137

Enhance postgres index filter with values from real life This has been found on fairly old instances of ours (cwo/elo). Dunno if we really want this in, it may lead to false negatives.