Add patch-id column to merge_request_diffs table

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/126920



Merged-by: Mehmet Emin INAC <minac@gitlab.com>
Approved-by: Terri Chu <tchu@gitlab.com>
Approved-by: Michał Zając <mzajac@gitlab.com>
Approved-by: Avielle Wolfe <awolfe@gitlab.com>
Approved-by: Mehmet Emin INAC <minac@gitlab.com>
Reviewed-by: Terri Chu <tchu@gitlab.com>
Co-authored-by: Kerri Miller <kerrizor@kerrizor.com>