SuperCat output can include non-OPAC-visible holdings

EG 3.1

SuperCat holdings include items which are not OPAC-visible. (See also bug 1794884.)

1. Add a copy to a MARC record. Set the copy's OPAC-visible flag to false.
2. View the record and holdings with SuperCat, e.g.: https://demo.evergreencatalog.com/opac/extras/supercat/retrieve/marcxml-full/record/$id

Expected behavior: Only OPAC-visible copies are shown.

Actual behavior: The non-OPAC-visible copy is included in holdings info. I believe this will also be true if the volume, shelving location, or org unit is not OPAC-visible.

For the marcxml-full format, I think we want the new_record_holdings() function in Application/SuperCat.pm to test for OPAC visibility. Other SuperCat record formats may require changes elsewhere.