Create Piece Records in Orders Storage for items quantity ordered on Order Placement

Purpose: Need a Piece Record in Orders Storage linked to PO Line and Item in Inventory to support receiving and check-in process as well as support receiving history.

High-Level Requirements:

• One Piece Record needs to be created in Orders Storage per unit of quantity identified in the order line record (in other words, a corresponding piece record should exist for each item record associated with PO line)
  • Item records may or may not be created for electronic resources (boolean on the POL). Piece records need to be created regardless.
• See the results of MODORDSTOR-30 for the details on Piece record schema
• Piece records are created when an order transitions to "open" workflow status, along with Instance, Holding and Item records in Inventory (except ongoing orders which are handle differently)
  • The ongoing order edge case will be handled in a separate story.
• the UUID of the po_line should be set in the po_line_id field in the piece record.
• the UUID of the item record should be set in the item_id field in the piece record.

Scenarios to handle:

• Create partial pieces for those pieces which are associated with item ids. Check for existing pieces so we are not duplicating them
• For `P/E Mix` order type, create pieces when item exists in the inventory for the corresponding location. Verify pieces are created for physical and electronic resources.
• For `P/E Mix` order type, check for existing pieces before creating new pieces so we are not duplicating them

Acceptance Criteria:

• unit tests are updated
• api tests are updated
• piece records are created as described above on order placement

See https://docs.google.com/spreadsheets/d/1se-a2owRfHLG5eaAZglx4vLvRClCKGp2wZCfD39ZJRY/edit#gid=121556715 for complete API listing