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/risk_test.go

@@ -627,7 +627,6 @@ func TestRisk_SubResolvers(t *testing.T) {
 							edges {
 								node {
 									id
-									title
 								}
 							}
 						}
@@ -642,8 +641,7 @@ func TestRisk_SubResolvers(t *testing.T) {
 				Documents struct {
 					Edges []struct {
 						Node struct {
-							ID    string `json:"id"`
-							Title string `json:"title"`
+							ID string `json:"id"`
 						} `json:"node"`
 					} `json:"edges"`
 				} `json:"documents"`