Bug 19204: Clean the tests a bit to reuse the same pattern

Bug 19204: Clean the tests a bit to reuse the same pattern

The same pattern is used several times in test:
checkout, checkin, get the debarment, compare the dates and remove the
debarment.
Let's move that to a separate subroutine

Sponsored-by: Goethe-Institut
Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>