Bug 19616: Add MARC21 505$g - Formatted Contents Note / Miscellaneous informatoin

Bug 19616: Add MARC21 505$g - Formatted Contents Note / Miscellaneous informatoin

This adds the subfield $g to the display of the 505 field in
staff and OPAC detail pages.

To test:
- Catalog some records using variations of 505
  Examples can be found in the LOC documentation:
  https://www.loc.gov/marc/bibliographic/bd505.html
- Verify that the display in staff and OPAC is still nice
  and now includes $g

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>