More fixes

- Add a set of template tags for rendering status codes
- Improve build API filtering
- Remove some outdated files
- Fix unit testing

InvenTree/build/api.py

@@ -38,7 +38,6 @@ class BuildList(generics.ListCreateAPIView):
     ]
 
     filter_fields = [
-        'part',
     ]
 
     def get_queryset(self):
@@ -49,6 +48,12 @@ class BuildList(generics.ListCreateAPIView):
 
         build_list = super().get_queryset()
 
+        # Filter by part
+        part = self.request.query_params.get('part', None)
+
+        if part is not None:
+            build_list = build_list.filter(part=part)
+
         # Filter by build status?
         status = self.request.query_params.get('status', None)