postgresql: improve db.origin_visit_status_add to fix possible replayer issues

In case of an existing OriginVisitStatus entry (typically with the 'created' status), adding a new version of this entry should do an update instead of ignoring it. This could happen during a replayer session where the insertion of the OriginVisit used to automatically create an OriginVisitStatus in "created" status. This would then prevent the following replayer to actually insert the correct OriginVisitStatus.

Closes #4704 (closed)