👔(backend) display css and code in template endpoint

We would like to duplicate a template from the frontend.
For that we need to access the css and code of the template.
So we add the css and code to the template endpoint.

src/backend/core/api/serializers.py

@@ -157,16 +157,6 @@ class TemplateSerializer(BaseResourceSerializer):
         ]
         read_only_fields = ["id", "accesses", "abilities"]
 
-    def to_representation(self, instance):
-        """
-        Modify the output of serialization.
-        """
-        representation = super().to_representation(instance)
-        # Remove 'css' and 'code' from the representation
-        representation.pop("css", None)
-        representation.pop("code", None)
-        return representation
-
 
 # pylint: disable=abstract-method
 class DocumentGenerationSerializer(serializers.Serializer):