✨(backend) add async triggers to enable document indexation with find

On document content or permission changes, start a celery job that will call the
indexation API of the app "Find".

Signed-off-by: Fabre Florian <ffabre@hybird.org>

src/backend/core/utils.py

@@ -1,8 +1,8 @@
 """Utils for the core app."""
 
 import base64
-from collections import defaultdict
 import re
+from collections import defaultdict
 
 import pycrdt
 from bs4 import BeautifulSoup