Bug 35398: Add unit test for extraction of library_rotation_plan

Bug 35398: Add unit test for extraction of library_rotation_plan

This unit test addition adds an LRP segment to the test EDI message file
and adds the corresponding test to confirm is it extracted into the
field as expected.

Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 6744b9979a5b7029f9d35d19e680f8a03fcd8a75)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit 425bc1240b8786caaa2b414d2f884922b3b1511f)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>