[refactor] Optional prefetch (#11012)

* Automatic prefetch of related fields for enable_filter

- Allows us to *not* prefetch fields (expensive) when they are not going to be used
- Enables re-usable components for common detail fields

* Refactor "project_code_detail" filter into common component

- Automatically apply correct prefetch fields

* Refactor 'parameters' annotation

- add 'enable_parameters_filter' function
- Prefetch parameters only when needed
- Refactor / consolidate code

* Refactor SupplierPartSerializer

- Make fields switchable
- Ensure correct prefetch_related

* Refactor serializer for ManufacturerPart

* Refactor BuildSerializer

* Refactor PurchaseOrderSerializer

* Refactor SalesOrderSerializer

* Refactor ReturnOrderSerializer

* Remove debug statements

* Tweaks

* Simplify custom filterable fields

* Bump API version

* Fix for data export

* Additional unit tests

* Remove unused "prefetch_func" option

* Refactor PurchaseOrderLineItemList

* Refactor SalesOrderLineItemList

* Refactor ReturnOrderLineItem

* Cleanup "pretty_name"

* Fix for build list

* Refactoring StockItem API endpoint

- Needs significant work still

* Refactoring for BuildLineSerializer

* Keep all optional fields when exporting data

* Improve "UserRoles" API endpoint

- Prefetch roles
- Prevents significant number of db hits

* Prefetch Parameter API list

* Bug fix for exporting logic

* Specify InvenTreeOutputOption

* Optional prefetch for primary_address

* Fix typing

* Fix unit test

* fixes for playwright tests

* Update Part API

- Improved prefetching

* Fix for prefetch

src/backend/InvenTree/order/models.py

@@ -1989,17 +1989,16 @@ class PurchaseOrderLineItem(OrderLineItem):
     def get_destination(self):
         """Show where the line item is or should be placed.
 
-        NOTE: If a line item gets split when received, only an arbitrary
-              stock items location will be reported as the location for the
-              entire line.
+        1. If a destination is specified against this line item, return that.
+        2. If a destination is specified against the PurchaseOrderPart, return that.
+        3. If a default location is specified against the linked Part, return that.
         """
-        for item in stock.models.StockItem.objects.filter(
-            supplier_part=self.part, purchase_order=self.order
-        ):
-            if item.location:
-                return item.location
         if self.destination:
             return self.destination
+
+        if self.order.destination:
+            return self.order.destination
+
         if self.part and self.part.part and self.part.part.default_location:
             return self.part.part.default_location