Bug 14617: Add fields to ISBN and ISSN indexes: 020$z, 022$y, 022$z

Bug 14617: Add fields to ISBN and ISSN indexes: 020$z, 022$y, 022$z

1) Import MARC21 bibs containing

- ISBN in 020$z
- ISSN in 022$y
- ISSN in 022$z

2) Make sure that bibs are indexed

3) Search by ISBN and ISSN above -- bibs should not show in search.

4) Apply patch, re-index

5) Search again; ISBN in 020$z and ISSN in 022$y and 022$z should return
results.

Signed-off-by: kholten@switchinc.org
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>