Bug 11797: add regression test

Bug 11797: add regression test

This patch adds unit tests for C4::AuthoritiesMarc::BuildSummary
for both UNIMARC and MARC21 and a regression test for the "Odd
number of elements in anonymous hash" warning.

To test:

[1] Run prove -v t/db_dependent/AuthoritiesMarc.t.  It should
    report one failure.
[2] Apply the main patch.
[3] Run t/db_dependent/AuthoritiesMarc.t again; it should pass.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit f2b655dfabc4a4464099e7d9bc219b6714ef7de1)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>