Bug 11550: Add UT for C4::Acquisition::GetOrder

Bug 11550: Add UT for C4::Acquisition::GetOrder

If GetOrder is called with a nonexistent ordernumber or without any
ordernumber, it should return undef.

Test plan:
prove t/db_dependent/Acquisition.t

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Updated number of tests to 68, tests and QA script all happy now.
Looked at a few pages in aquisition using GetOrder as well.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 0b35290011a48938b55a069c2e44eee688bf70c8)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Conflicts:
	t/db_dependent/Acquisition.t