fdo#84504: UI- LineNumbering for header/footer

Change-Id: I5b432273ce24d8575ac36f5336717669db733c35
Reviewed-on: https://gerrit.libreoffice.org/11730
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>