PARIS — The Grand Tour quite literally provided the point of departure for Maria Grazia Chiuri and Pierpaolo Piccioli’s women’s Spring 2015 ready-to-wear collection for Valentino. The 18th-century rite of passage of young people from certain strata of European society was notably dressed up for modern times Monday afternoon when Belgian model Yana opened the show under the tents in the Tuileries. Yana went on to feature another pair of looks on the runway in the show and was joined by Maja Salamon, Grace Si