Move document title ownership from document to version

Title is now owned by document_versions, following the same pattern as
classification and document_type. The documents.title column is made
nullable with a TODO to drop it. Backend loads title from a
latest_versions CTE for ordering purposes only. The frontend resolves
title from the latest version, and DocumentTitleForm now operates on
DocumentVersion using UpdateDocumentVersion mutation.

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

e2e/console/employee_document_test.go

@@ -55,7 +55,6 @@ func TestEmployeeDocument_NodeAccess(t *testing.T) {
 				node(id: $id) {
 					... on Document {
 						id
-						title
 					}
 				}
 			}
@@ -71,7 +70,6 @@ func TestEmployeeDocument_NodeAccess(t *testing.T) {
 				node(id: $id) {
 					... on Document {
 						id
-						title
 					}
 				}
 			}