Bug 19130: Remove ->search() overloading and adjust tests

Bug 19130: Remove ->search() overloading and adjust tests

This patch removes the custom ->search() function. Tests are adjusted
so the results from ->search() calls are not expected to return in the
previously hardcoded order.

To test:
- Apply this patch
- Run:
  $ sudo koha-shell kohadev
 k$ cd kohaclone
 k$ prove t/db_dependent/Bookseller.t
=> SUCCESS: Tests pass
- Sign off :-D

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