Add MergeRequestDiffFileComponent to Rapid Diffs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183592



Merged-by: Phil Hughes <me@iamphill.com>
Approved-by: Thomas Randolph <trandolph@gitlab.com>
Approved-by: Phil Hughes <me@iamphill.com>
Approved-by: Jacques Erasmus <jerasmus@gitlab.com>
Co-authored-by: Stanislav Lashmanov <slashmanov@gitlab.com>