Merge branch '511839-repo-tree-table-row-headers' into 'master'

Ensure file tree table has row headers

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/179123



Merged-by: Sheldon Led <sheldonled@gitlab.com>
Approved-by: Sheldon Led <sheldonled@gitlab.com>
Co-authored-by: Chad Lavimoniere <clavimoniere@gitlab.com>