Bug 17941 add tests to cover the optimization of the nested loop

Bug 17941 add tests to cover the optimization of the nested loop

the new code skip testing for more borrowers if the item can't be renewed
this require more tests for the case where 2+ items are reserved.

I tried to add 1 more reserve to the main test suit, but too many other tests
rely on specific holds, and I couldn't get around it.

Instead, I added a subtest that consider the specific simple case and leave the
other test cases exactly has they were designed.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Amended-patch: Just fix 3 indendations

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>