The 1982 science fiction film “Blade Runner” may be among the youngest revivals at this year’s New York Film Festival, screening in a remastered edition dubbed “the final cut” alongside classics by John Ford and Josef von Sternberg. But as an enthused panel discussion suggested this weekend at the Walter Reade Theater, Ridley Scott’s adaptation of Philip K. Dick’s novel about artificial superhumans on the loose in 2019 Los Angeles lives on in more than one sense of the phrase.