Add additional supplemental files to CWL sv output, give useful names.

def _add_supplemental(data):
    """Add additional supplemental files to CWL sv output, give useful names.
    """
    if "supplemental" not in data["sv"]:
        data["sv"]["supplemental"] = []
    if data["sv"].get("variantcaller"):
        cur_name = _useful_basename(data)
        for k in ["cns", "vrn_bed"]:
            if data["sv"].get(k) and os.path.exists(data["sv"][k]):
                dname, orig = os.path.split(data["sv"][k])
                orig_base, orig_ext = utils.splitext_plus(orig)
                orig_base = _clean_name(orig_base, data)
                if orig_base:
                    fname = "%s-%s%s" % (cur_name, orig_base, orig_ext)
                else:
                    fname = "%s%s" % (cur_name, orig_ext)
                sup_out_file = os.path.join(dname, fname)
                utils.symlink_plus(data["sv"][k], sup_out_file)
                data["sv"]["supplemental"].append(sup_out_file)
    return data