Bug 11912: (regression tests) GetMarcISBN wrongly prepends a space to ISBNs

This patch makes the tests run in both MARC21 and UNIMARC contexts.
It previously run only for MARC21. It mocks what needs to be mocked.

To test, run
 - prove t/db_dependent/Biblio.t
=> Notice the first ISBN has a space in front of it and those tests fails.

Signed-off-by: Nicolas Legrand <nicolas.legrand@bulac.fr>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Bug 11912: fix problem where GetMarcISBN wrongly prepends a space to ISBNs

This patch makes the logic inside GetMarcISBN simpler and
fixes the issue.

To test:
- Run the regression tests:
  prove -v t/db_dependent/Biblio.t
=> FAIL
- Apply the patch
- Run:
  prove -v t/db_dependent/Biblio.t
=> SUCCESS
- Verify that opac-detail.pl and catalogue/detail.pl look as usual regarding ISBN
- Sign off

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: Nicolas Legrand <nicolas.legrand@bulac.fr>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Bug 11912: (refactoring followup) make GetMarcISBN implement its advertised API

The current implementation of GetMarcISBN contradicts the documented API.
It currently returns an array of hashes with only one key (marcisbn)
which doesn't add any value to it.

I chose to fix GetMarcISBN to honour the API instead of changing thex
 docs, because it seems a really silly change.

To test:
- Run:
  prove t/db_dependent/Biblio.t
=> SUCCESS
- catalogue/detail.pl should correctly show ISBNs.
- opac/opac-detail.pl should correctly show ISBNs in both prog and bootstrap.
- opac-opac-sendshelf.pl should correctly show ISBNs in the email.

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: Nicolas Legrand <nicolas.legrand@bulac.fr>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Bug 11912: (follow-up) Use the common way to mock syspref

t::lib::Mocks::mock_preference provides a simple way to mock syspref.

Test plan:
Verify that t/db_dependent/Biblio.t returns green.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>