Add "source_id" to Physical and Electronic Holdings Data

[kevinreiss]

User story

When multiple matching records are combined in a cluster the holdings data needs to retain the original record ID for use when supporting request and availability features.

Acceptance criteria

• Each physical holding object in the "holdings_1display" key has a new attribute "source_id" that stores the original Record ID.
• Each electronic object in the "electronic_portfolio_s" key has a new attribute "source_id" that stores the original Record ID.
• Each electronic object in the "figgy_1display" key has a new attribute "source_id" that stores the original Record ID.

Concrete example

"This is Happiness" is a record that has two electronic and two physical items.