Instance record with an underlying MARC record. Block edit of given elements if SRS MARC is linked (Part 2 of Connecting SRS, Inventory, and MARCCat for Bibs/Instances)

NOTE: During Q2 2019 planning, decided this will be handled by Folijet, consulting with Core-Fxn if needed for Inventory-related aspects

This is Part 2 of Connecting MARCcat, Source Record Storage, and Inventory for MARC Bibs/Instances: Block edit of Instance Elements maintained in the udnerlying MARC Bib record (UXPROD-1447)
See Part 1: Make Inventory Instance rely on SRS and update the standard mappings from SRS to Instance (UXPROD-1577)
See Part 3: Implement Instance-to-MARC Mapping, including spike for whether whether Inventory Instance influences SRS MARC Bibs in any way other than creating a brief SRS MARC Bib when one does not exist (UXPROD-1397)
See Part 4: SRS-MARCcat Integration (UXPROD-1595)

Purpose: When established linking between an Instance record in Inventory to a source record in the Source Record Storage (SRS), then edit of given meta elements in the Instance record need to be blocked, when data is maintained in the MARC record in MARCcat.

Requirements:

• Confirm which Instance data elements should be locked from editing and which are open for editing, when an underlying MARC record exists. Inventory back end will hold definitions of the un-editable fields; UI can read that and disable the un-editable fields. Will also relate to the fields that were mapped to create the Instance, when the SRS MARC was loaded.
• If Instance linked to underlying MARC, block edit of the specified fields
• How will UI indicate the fields are blocked from editing? Grey them out in the edit screen
• Ensure that all fields in instances without underlying MARC records are still editable

In the instance record the element Metadata source is implemented (in alpha). This element is auto-populated with the specific source of the record in the SRS, if applicable. Current valid values are MARC (if underlying SRS MARC record) or FOLIO

Dependencies:

1. Establish storage of MARC formatted records in SRS
2. Implement data flow Inventory <> SRS <> MARCcat