✨(backend) add new ability on document "accesses_view"

We need this ability in the frontend to know whether we should try
to display the list of users who have document accesses. If this
ability is False (e.g for anonymous users), we should only show
the link reach and link role when clicking on the "Share" button.

src/backend/core/tests/templates/test_api_templates_retrieve.py

@@ -22,7 +22,7 @@ def test_api_templates_retrieve_anonymous_public():
         "abilities": {
             "destroy": False,
             "generate_document": True,
-            "manage_accesses": False,
+            "accesses_manage": False,
             "partial_update": False,
             "retrieve": True,
             "update": False,
@@ -68,7 +68,7 @@ def test_api_templates_retrieve_authenticated_unrelated_public():
         "abilities": {
             "destroy": False,
             "generate_document": True,
-            "manage_accesses": False,
+            "accesses_manage": False,
             "partial_update": False,
             "retrieve": True,
             "update": False,