GIORGIO BASSANI'S FERRARA MAY BE, AS AN AMERICAN critic has called it, a "semiotic labyrinth," but it is no doubt a very faithful representation of this city, of its history and topography. Actually, the success of his works, especially of his Giardino dei Finzi Contini (The Garden of the Finzi Continis), a novel that remained for years at the top of the best-sellers list, and in this country the even bigger success of the Oscar winning movie adapted from that novel and directed by ...