Fix missing updated time on migrated issues and comments (#9744)

* Fix missing updated time on migrated issues and comments

* Fix testing and missing updated on migrating pullrequest

Co-authored-by: Antoine GIRARD <sapk@users.noreply.github.com>

modules/migrations/base/comment.go

@@ -14,6 +14,7 @@ type Comment struct {
 	PosterName  string
 	PosterEmail string
 	Created     time.Time
+	Updated     time.Time
 	Content     string
 	Reactions   *Reactions
 }