TEST: label_vertebrae: added relevant integrity testing measure
TEST: label_vertebrae: added relevant integrity testing measure

Former-commit-id: e9f4ab7d1321a505a8ffc830bd521536db5eb332
Former-commit-id: 09e095c83e20e592f7dab45eb4f2b143d1ec413e
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox