Nearly two years after retail whispers hinted at plans for a new Dolce & Gabbana boutique in New York City, the luxe Italian label opened shop last week at 715 Fifth Ave. Housed in Escada’s former digs, the 11,000-square-foot store is Dolce & Gabbana’s newly minted US flagship, complete with trimmings as opulent as the brand’s striking designs. Doors to the 16-year-old Madison Avenue boutique will remain open.