CityCenter DC is humming. People have begun moving into the apartments, the condos are selling, a few shops are open and 10th Street, after 35 years, has re-opened. The project’s developer is also readying to unveil a retail line-up that, according to a source familiar with the negotiations, will likely include Dior, Hermès, Longchamp, Paul Stuart, Salvatore Ferragamo and Zadig & Voltaire.