Once upon a time the great Duke Ellington designated the equally great Ella Fitzgerald as "beyond category," an honor to be used sparingly. So while she's widely known now as "The Marvelous Marilyn Maye," it's ever more clear that this wondrous diva is much more than that"she's easily beyond category. In this latest gig of her life of almost continuous performance (the stage is her true home), a year-end run in the B…