The singer performed ‘Training Season,’ ‘Houdini,’ ‘Happy for You’ and ‘Illusion,’ off of her new album ‘Radical Optimism,’ during the impromptu show Dua Lipa had a busy weekend! Less than 24 hours after pulling double duty as host and musical guest on Saturday Night Live, the 28-year-old singer put on a surprise performance in New York City on Sunday, May …