There are too many files in `models/migrations` folder so that I split them into sub folders.
* deleteIssuesByRepoID: delete related CommentTypeRemoveDependency & CommentTypeAddDependency comments too * Ignore ErrIssueNotExist on comment.LoadDepIssueDetails() * Add migration * Ignore 'dependent_issue_id = 0' case * exchange as per @lunny Co-authored-by: techknowlogick <techknowlogick@gitea.io>