Merge branch 'ph/414758/setDiffView' into 'master'

Init diffViewType inside setupMrNotesState

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/124458



Merged-by: Andrew Fontaine <afontaine@gitlab.com>
Approved-by: Andrew Fontaine <afontaine@gitlab.com>
Approved-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Co-authored-by: Phil Hughes <me@iamphill.com>