A new coffee-table book looks beyond the island’s reputation as a queer summer utopia, revealing it, for the first time, as a creative hub that influenced artists from Richard Avedon to Wolfgang Tillmans By Jeanne Malle Fire Island Art: 100 Years is “only masquerading as a coffee-table book,” its editor, John Dempsey, said at the launch party in late March. On the top floor of the Nine Orchard hotel, on Manhattan’s Lower East Side, a group of me…