Bug 17430: Make MarkIssueReturned.t create its own data

Bug 17430: Make MarkIssueReturned.t create its own data

This patch makes MarkIssueReturned.t use t::lib::TestBuilder to create
the data it needs.

To test:
- On master, have a category with categorycode = C
- Run:
  $ prove t/db_dependent/Circulation/MarkIssueReturned.t
=> FAIL: primary key problems make the tests fail
- Apply the patch
- Run:
  $ prove t/db_dependent/Circulation/MarkIssueReturned.t
=> SUCCESS: Tests are green!
- Sign off :-D

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>