total_price for orders (#4447)

* Adds unit test for counting queries on PurchaseOrderList API endpoint

- We will work to make this queryset more efficient

* PEP fixes

* Add 'total_price' fields to SalesOrder and PurchaseOrder models

* PurchaseOrder list API now has constant query count

* Data migration for updating existing PurchaseOrder and SalesOrder instances

- Calculate total_price for any existing order
- Will fail if exchange rates are not available

* Add total_price_currency to API serializers

* Render total_price in SalesOrder table

* Add ability to filter both lists by total_price field

* Update total_price whenever an order is updated

* Update total price whenever a lineitem is saved or deleted

* Add query-counting unit test for SalesOrder list API

* Calling refresh_from_db inside a save() method is *not* a good idea

InvenTree/templates/js/translated/order.js

@@ -2155,9 +2155,11 @@ function loadPurchaseOrderTable(table, options) {
                 field: 'total_price',
                 title: '{% trans "Total Cost" %}',
                 switchable: true,
-                sortable: false,
+                sortable: true,
                 formatter: function(value, row) {
-                    return formatCurrency(value);
+                    return formatCurrency(value, {
+                        currency: row.total_price_currency,
+                    });
                 },
             },
             {
@@ -2979,6 +2981,17 @@ function loadSalesOrderTable(table, options) {
                 field: 'line_items',
                 title: '{% trans "Items" %}'
             },
+            {
+                field: 'total_price',
+                title: '{% trans "Total Cost" %}',
+                switchable: true,
+                sortable: true,
+                formatter: function(value, row) {
+                    return formatCurrency(value, {
+                        currency: row.total_price_currency,
+                    });
+                }
+            }
         ],
     });
 }