This module will add the purchase order line to journal items.
The ultimate goal is to establish the purchase order line as one of the key fields to reconcile the Goods Received Not Invoiced accrual account.
Field purchase_line_id_oca it's necessary. In Odoo >=16 automatic revaluation for a product with FIFO costing method only works if invoice lines related to a purchase order line do not include stock journal items. To aviod that purchase_line_id_oca includes invoice and stock journal items, and we keep Odoo field invoice_lines just with bill lines. - Check issue #2017