Bug 7695 - Change boolean operator from "and" to "AND"

Bug 7695 - Change boolean operator from "and" to "AND"

When XSLTDetailsDisplay/OPACXSLTDetailsDisplay = on and
TraceSubjectSubdivisions = Include, subject sudivisions are
combined with the boolean operator "and". Currently, this word is
translated along with other occurrences of the same word, resulting
in a false "no records found" for users of non-English templates.

This patch replaces "and" with "AND" which should have no effect on
searching (since Zebra is case-insensitive in this regard) but will
make the boolean operator stand out from other uses of "and" in
translations.

TraceSubjectSubdivisions is currently only implemented in MARC21,
so UNIMARC and NORMARC is not affected.

To test:

XSLTDetailsDisplay/OPACXSLTDetailsDisplay = using XSLT
TraceSubjectSubdivisions = Include
marcflavour = MARC21

Find a record with a clickable subject that includes one or more
subdivisions and check that the subdivisions are combined with
"AND", not "and". Check that you get the expected result when
clicking on the subject.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Easy to test and works as advertised.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>