Bug 5262: make authority plugin copy indicators to bib record

With this patch Koha should correctly copy indicators
(and create $2 subfield in MARC 21 if need) from the chosen authority
record to the edited bibliographic record (according to discussion in
bugzilla). UNIMARC and MARC 21 flavors are covered.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>

Comment: work as described, testing in comments 9 and 12.
No errors.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes QA script and tests. Tested functionality repeating
some of the tests noted by Bernardo - checking mostly 1xx, 490,
and 7xx.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>