Bug 18277: Remove GetBiblionumberFromItemnumber - Easy ones

Bug 18277: Remove GetBiblionumberFromItemnumber - Easy ones

To retrieve a biblionumber from an itemnumber, we can use:
  Koha::Item->biblio->biblionumber

This is only what this patchset does.
Doing that we will be able to get rid of the
C4::Biblio::GetBiblionumberFromItemnumber subroutine.

Test plan:
- Acquisition module: cancel a receipt
- Export a record to CSV
- Modify items in a batch

Item's info should be correct

Other changes with be checked by QA team, by reading the code.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>