Prevent dupe record IDs from being returned by authority browse/startwith

Prevent dupe record IDs from being returned by authority browse/startwith

The 4xx/5xx .ref variants on the authority browse/startwith methods
could return duplicate records if a 1xx/4xx/5xx contained similar entries,
which was highly irritating in the user interfaces.

I haven't been able to figure out a way to use just json_query to return
a set of unduped records that are still ordered appropriately, so I'm
fixing it in post-production... roughly. There is probably a better way
to do this (create an SQL function and select from that, perhaps) but
this at least appears to be an improvement over the current state of affairs.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@19139 dcc99617-32d9-48b4-a31d-7c20da2025e4