Fix logic around showing search box

It was looking at the count of items at the root level (because it was
passing `parent_folder_id=None` as an argument).

This changes it to look at the total count of items for a service (which
was the intended behaviour).

app/models/service.py

@@ -369,7 +369,7 @@ class Service():
 
     @property
     def count_of_templates_and_folders(self):
-        return len(self.get_template_folders_and_templates('all', None))
+        return len(self.all_templates + self.all_template_folders)
 
     def move_to_folder(self, ids_to_move, move_to):