Bug 10306: Add tests for module changes

Bug 10306: Add tests for module changes

GetMarcSubfieldStructure: In Biblio.t we are adding a subtest that checks
the structure returned by this routine. Is it a hashref pointing to
arrayrefs of hashrefs? ;)
In Search.t this routine was mocked. The change in the returned structure
is now applied to this mock too (moving the marc tag hashes into
arrayrefs).

GetMarcFromKohaField: In Biblio.t we add a subtest for it. We are checking
if it returns multiple mappings (per kohafield) and calling it in scalar
context too.

GetMarcSubfieldStructureFromKohaField: The existing subtest in Biblio.t is
expanded to also test the call in list context.

TransformKohaToMarc: This sub has its own test script. We are adding a
subtest in TransformKohaToMarc.t for a test with multiple mappings,
and for mapping to a control field in another framework. This also tests
the additional framework parameter.
Additionally, we add a test for the new no_split option used for items.

TransformMarcToKoha: This implicitly tests its helper sub _get_inverted.
This patch adds a new test script for this routine.

TransformMarcToKohaOneField: A few tests are added to the previous new
test script.

Test plan:
[1] Run t/db_dependent/Biblio.t
[2] Run t/db_dependent/Biblio/TransformKohaToMarc.t
[3] Run t/db_dependent/Biblio/TransformMarcToKoha.t
[4] Run t/db_dependent/Search.t

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>