[common][utils] annotate_full_name on query rather than starting on class

This will allow the use of model managers.

beat/web/common/utils.py

@@ -149,13 +149,13 @@ def py3_cmp(a, b):
     return (a > b) - (a < b)
 
 
-def annotate_full_name(db_class):
+def annotate_full_name(query):
     """
     Annotate a query with the asset full name so that it can be more easily
     filtered.
     """
 
-    return db_class.objects.annotate(
+    return query.annotate(
         full_name=Concat(
             "author__username",
             V("/"),