There’s a huge star at the center of the Sydney Theatre Company’s much-hyped, Liv Ullman-directed, wholly satisfying new staging of A Streetcar Named Desire, which sold out its Kennedy Center run before the curtain rose on the first preview. I speak, of course, of the dramatist Tennessee Williams. That’s no slight on Cate Blanchett, who fronts, fights, twirls and finally, crawls her way through a towering, plaintive gut-punch of a performance as Blanche DuBois,…