Generate MARC bib record - 336 $a/instanceTypeId - replacing keys with values

Purpose
FOLIO inventory storage instance contains fields that are represented by keys and those will need to be replaced by their values when generating MARC bib record on the fly. For example, an inventory instance record contains, instanceTypeId field that will be used to populate the 336 $a MARC field and we will need to retrieve the value of the key stored in the instanceTypeId so that MARC field can be populated correctly.

This user story covers instanceTypeId – the value used to populate 336 $a comes from the "name" field in instanceType

Since the records will be generated in parallel to retrieving records from SRS the formatting should not require any addition data manipulation by the consumer of the data and is formatted consistently with parsedRecord.json.

Acceptance criteria

1. The generated record is short-lived and generated each time it is requested
2. The record is saved in .mrc file and contains 336$a field populated with the correct data
3. Both indicators are blank
4. Unit tests are written
5. API tests are written

Note: For the MARC record indicator value check: https://docs.google.com/spreadsheets/d/11lGBiPoetHuC3u-onVVLN4Mj5KtVHqJaQe4RqCxgGzo/edit#gid=1410366280 "Concorde - Instance to MARC 2019" tab