OPT: added adv_param flag for MAP implementation of sct_extract_metric
OPT: added adv_param flag for MAP implementation of sct_extract_metric

Former-commit-id: 0d6e557f9a47f48ac33cdbad79c3cff8055b5562
Former-commit-id: c2e99e8e16ef42712c49a455b7ff68b410de1514
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox