Bug 12868: Improving t/db_dependent/Member.t

Bug 12868: Improving t/db_dependent/Member.t

The mock function of GetMemberAccountRecord did not properly
account for the undef case. This was corrected.

Then all 4 combinations of borrower number and card number being
defined or not were called to GetMemberDetail.

The problematic test case is where the borrower number is
undefined and the cardnumber is defined.

TEST PLAN
---------
1) Apply just this first patch.
2) prove -v t/db_dependent/Member.t
   -- This should fail!
3) Run koha QA test tools.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>