Add a new set of unapi/supercat holding-enriched formats, -uris

Add a new set of unapi/supercat holding-enriched formats, -uris

These formats focus on returning just URIs, rather than the bulky copy
information returned by -full. Accordingly, the default data type
requested by BibTemplate.js has been changed to 'marcxml-uris', as
out of the box no functionality in the default or craftsman skins
require copy information.

Some of the duplicate code in OpenILS::WWW::SuperCat.pm has been refactored
into subroutines.

To aid the human reader of the -uris and -full output, line breaks
and indentation has been introduced to the contents of the <volumes> element.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@14802 dcc99617-32d9-48b4-a31d-7c20da2025e4