Comment 6 for bug 1853006

Thanks, Zavier

Since you're moving part of the required logic into basic_opac_copy_query() to get the flag out, perhaps we should just move the rest into basic_opac_copy_query() and have it be driven by an optional parameter, just like the staff flag. With that change other callers can benefit from the ability to filter by copy availability in the future.

Thoughts?