When theKaufhaus des Westens (KaDeWe), a temple of consumption in West Berlin, celebrated its 115th birthday last month with a glitzy champagne party for 2,000, the mood was sparkling. A row of brightly lit Christmas trees greeted partygoers when they entered the ground floor of the grand old lady of Berlin’s department stores, where Chanel, Dior, Gucci, Tiffany’s and other luxury brands vie for their attention. As guests danced through…