✨(documents) allow retrieving versions (list and detail)

Versions are retrieved directly from object storage and served on API
endpoints. We make sure a user who is given access to a document will
only see versions that were created after s.he gained access.

src/backend/core/tests/documents/test_api_documents_retrieve.py

@@ -24,6 +24,9 @@ def test_api_documents_retrieve_anonymous_public():
             "partial_update": False,
             "retrieve": True,
             "update": False,
+            "versions_destroy": False,
+            "versions_list": False,
+            "versions_retrieve": False,
         },
         "accesses": [],
         "title": document.title,
@@ -66,6 +69,9 @@ def test_api_documents_retrieve_authenticated_unrelated_public():
             "partial_update": False,
             "retrieve": True,
             "update": False,
+            "versions_destroy": False,
+            "versions_list": False,
+            "versions_retrieve": False,
         },
         "accesses": [],
         "title": document.title,