BOM Table Improvements (#3310)

* Bug fix for "multi delete" form

- Was requesting entire LIST endpoint before launching form
- Could cause extremely long delays before window opened

* Improve rendering of "no stock available" in BOM table

* Adds footer row to BOM table

- Display total number of parts
- Display minimum "can build" amount

* Added extra information to footer row

* Annotate 'ordering' quantity to BOM list

- Display this quantity in the BOM table

* Bump API version

* JS linting

* Allow BOM list to be filtered by "on_order" parameter

* Add information showing amount that can be built once orders are received

InvenTree/part/serializers.py

@@ -524,6 +524,8 @@ class BomItemSerializer(InvenTreeModelSerializer):
 
     purchase_price_range = serializers.SerializerMethodField()
 
+    on_order = serializers.FloatField(read_only=True)
+
     # Annotated fields for available stock
     available_stock = serializers.FloatField(read_only=True)
     available_substitute_stock = serializers.FloatField(read_only=True)
@@ -593,6 +595,11 @@ class BomItemSerializer(InvenTreeModelSerializer):
 
         ref = 'sub_part__'
 
+        # Annotate with the total "on order" amount for the sub-part
+        queryset = queryset.annotate(
+            on_order=part.filters.annotate_on_order_quantity(ref),
+        )
+
         # Calculate "total stock" for the referenced sub_part
         # Calculate the "build_order_allocations" for the sub_part
         # Note that these fields are only aliased, not annotated
@@ -719,6 +726,8 @@ class BomItemSerializer(InvenTreeModelSerializer):
             'available_substitute_stock',
             'available_variant_stock',
 
+            # Annotated field describing quantity on order
+            'on_order',
         ]