Mapping profile - transformations - process holdings and items simple fields

As a librarian exporting inventory data I would like to have records contain the electronic access data so that items information is appended to inventory instance records when exporting in the MARC format

Scenario 1:
Given: any field associated with the item electronic access has associated transformation
When: the inventory instance record has an inventory item record with populated electronic access data
Then: the data that is stored in the item record is used to populate fields as specified in the transformation and the MARC fields are appended to MARC bib record

Scenario 2:
Given: any field associated with the item electronic access has associated transformation
When: the inventory instance record has an inventory item record without electronic access data
Then: the mapping is skipped and no fields are appended to the MARC bib record

Note: User story covers transformation of the fields:
Holdings - Call number - prefix
Holdings - Call number
Holdings - Call number - suffix
Holdings - Electronic access - Link text
Holdings - Electronic access - URI
Items - Effective call number
Items - Electronic access - Link text
Items - Electronic access - URI

Additional Acceptance criteria:

1. Unit tests are written
2. API tests