SPIKE: Instance & SRS record updates need to honor MARC field protections

Grooming - does this need to be broken into multiple bugs/stories?

Overview: When updating instance records with an implied action of updating the SRS MARC record, field protections entered in Settings need to be honored. Currently the existing SRS MARC is replaced with the new record and the protected fields are erased.

Current workaround: No workaround; existing protected fields are deleted. They must be recreated (if one can remember what was in them).

Steps to Reproduce:

1. Log into FOLIO-snapshot as diku_admin
2. Add a MARC field into Settings: Data Import: MARC field protection (ex. field 981, ind 1 = *, ind 2 = *, subfield = *, data = *) and Save.
3. Import a record using a job profile to create an instance only, and make sure the MARC record has the protected field (ex. 981).
4. Update the record using a job profile with a match: for matches, update instance, and a MARC record that lacks the protected (ex. 981) field.

Expected Results: The instance updates, and the SRS record updates, with the 981 field from the original record remaining in the updated SRS record.

See examples and additional explanation here: https://wiki.folio.org/display/FOLIJET/MARC+field+protections

Actual Results: The instance updates, and the SRS record updates; however the update wipes out the protected 981 field.

Additional Information: Field protections also need to occur with single-record-import overlays, which may need an additional JIRA, or may be covered by a fix here.

NOTE Once this bug is fixed, review field protection overrides.