purchase order and agreement tracking

We received a feature request from a customer regarding purchase order and agreement tracking in the system:

• Client Purchase Order (LPO) Tracking: Enable tracking for client LPOs so that all sales invoices can be linked directly against them, giving full visibility into what remains to be invoiced.
• Supplier Agreement & PO Tracking for Bills: Enhance bill/purchase tracking to support tracking against Supplier Agreements or POs, linking all supplier invoices against them to monitor remaining uninvoiced supplier balances.