✨(backend) add subrequest auth view for collaboration server

We need to improve security on the access to The collaboration server
We can use the same pattern as for media files leveraging the nginx
subrequest feature.

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to
 
 ## Changed
 
+- 🔒️(collaboration) increase collaboration access security #472
 - 🔨(frontend) encapsulated title to its own component #474
 - 🐛(frontend) Fix hidden menu on Firefox #468
 - ⚡️(backend) optimize number of queries on document list view #411