LP#1992827: Improve OPAC URI display

LP#1992827: Improve OPAC URI display

Currently, the web staff client displays URIs in a slightly different
(and arguably better/more complete) way than the OPAC. In particular,
the staff client includes any 856 with an ind2 value of 0, 1, or 2, and
provides a label indicating the purpose of the URI based on the ind2
value. The OPAC, on the other hand, only displays 856s with an ind2 of 0
or 1, and does not distinguish the purpose.

This commit both implements the "purpose" labeling and allows ind2=2
URIs to be displayed.  Both BooPAC and TPAC templates are adjusted.

This does not change the way Located URIs are excluded from OPAC
display, they are still filtered out based on the existence of subfield
9.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Christine Morgan <cmorgan@noblenet.org>
Signed-off-by: Jane Sandberg <js7389@princeton.edu>