Ah, tragic love. Wolf Trap was awash in it — not to mention aerial sword fights, blood-soaked revenge, thundering armies on horseback and all that other irresistible stuff — on Friday night, when the composer Tan Dun brought his hot-off-the-presses “Martial Arts Trilogy” to the Filene Center stage. Dun, of course, is the Chinese composer who burst into the mainstream after winning an Oscar for his score to the 2000 blockbuster “Crouching Tiger, Hidden Dragon,” famous for its balletic, gravity-defying martial arts.