Synchronize omoccurdeterminations with values in omoccurrences when updating a snapshot

[themerekat]

When you update a snapshot from a file that does not have an identifications file (surprisingly common), the identifications table doesn't get re-populated from omoccurrences, resulting in mismatched values in omoccurrences and omoccurdeterminations.

(this will be fixed when the taxonomy in omoccurrences is deprecated in favor of omoccurdeterminations, but we might need a back-compatible fix in the meantime)