Tributes to Alain Delon, who died last week at the age of 88, have honoured the heartthrob actor as one of France’s most memorable leading men. But fans may have been surprised to read about his forays into furniture design. Most notably, he conceived a collection in the 1970s for the rarefied French design house, Maison Jansen. It turns out he wasn’t so unusual for having a double artistic passion. They may be global icons who’ve carved a path to the pinnacle of their creative professions, but some of the world’s biggest stars have also led a creative double life away from their day jobs. Jon…