More work

- Consolidated "in_stock" filter to single code location
- Improve 'limit_choices_to' for BuildItem and SalesOrderAllocation
- Various template improvements etc

InvenTree/build/api.py

@@ -53,6 +53,8 @@ class BuildList(generics.ListCreateAPIView):
     
     def filter_queryset(self, queryset):
 
+        queryset = super().filter_queryset(queryset)
+
         # Filter by build status?
         status = self.request.query_params.get('status', None)