Bug 29786: Unit tests

Bug 29786: Unit tests

I add a new test for the case of an item level hold, and additionally
adjust later tests to use a title level hold.

I also fix a typo where the comment says item 1 when it means item 2

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>