add MIN_SSNR to create_report_pages.py

# expected columns. actual columns are filtered from the incoming data later, this

# is mainly for controlling the order in the output table

COLUMNS = ["testcase", "Result", "MLD", "MAXIMUM ABS DIFF"]

COLUMNS = ["testcase", "Result", "MLD", "MAXIMUM ABS DIFF", "MIN_SSNR"]

COLUMNS_GLOBAL = COLUMNS[:1]

COLUMNS_DIFFERENTIAL = COLUMNS[1:]

COLUMNS_DIFFERENTIAL_NOT_MLD = COLUMNS_DIFFERENTIAL[2:]

def create_subpage(

    html_out,

    csv_out,