''Harree Pottah'' may be a smash box office hit in America but in Japan the current sensation is ''Sen to Chihiro no Kamikakushi,'' an animated fantasy about a sulky, pudgy-faced, 10-year-old girl trapped in a bathhouse with Japanese gods and spirits. Ultimately, the heroine rises from sulkiness to fend off dragons and sorceresses while trying to lift a curse on her parents, who were turned into p