What would it look like if Danish auteur Nicolas Winding Refn took a stab at a superhero show? If one guessed neon-soaked, with a penchant for nihilism and framed through the throbbing tempo of synthesizer beats, they would be correct, of course. NWR’s familiar triad of sorrow, synth, and neon guides his latest, Netflix’s six-part series “Copenhagen Cowboy.” The sprawling show trails Miu (Angela Bundalovic), an unlikely heroine presented as a non-descript magical entity whose powers go from healing long-lasting migraines to allowing post-menopausal women another shot at fertility.