Bug 29148: Check if hold is item or bib level

Bug 29148: Check if hold is item or bib level

To test:
1 - place an item level hold, it says: [one of the barcodes] or any available
2 - place a bib level hold, it says: [one of the barcodes] or any available
3 - Apply patch
4 - item level hold should say: Only [barcode]
5 - bib level hold should say: [one of the barcodes] or any available

Signed-off-by: Azucena <Azucena.Aguayo@uvu.edu>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>