LP#1743650: Bib vis testing needs different handling

LP#1743650: Bib vis testing needs different handling

For bib-level visibility testing, we can only use the source helper for
positive inclusion, and have to deal with LURIs on a case-by-case basis.
This is because, unlike the copy visibility cache, the LURI cache is pre-
composed in a single value for all LURIs on a record, not separate ones
for each.  This is fine, as we just need to find the effectively visible
org units and test for that subset of the relevant orgs. This commit provides
a sub to test for that, and handles LURI test composition at the perl
level rather than in the database.

Signed-off-by: Mike Rylander <mrylander@gmail.com>