fix: Billing % Logic and Map Pending Qty only in PR and DN

- Billing % should consider unreturned amount as total
- While mapping to return doc, map unreturned amount
- Added field Received Qty in Stock UOM, to tally against Returned Qty in PR
- PR billing percentage updation custom function
- In patch set received qty in stock uom first, then update returned qty and billing

erpnext/public/js/controllers/buying.js

@@ -189,6 +189,7 @@ erpnext.buying.BuyingController = erpnext.TransactionController.extend({
 
 			frappe.model.round_floats_in(item, ["qty", "received_qty"]);
 			item.rejected_qty = flt(item.received_qty - item.qty, precision("rejected_qty", item));
+			item.received_stock_qty = flt(item.conversion_factor, precision("conversion_factor", item)) * flt(item.received_qty);
 		}
 
 		this._super(doc, cdt, cdn);