LONDON " Wizarding legend Harry Potter's tale has turned 20.Author J.K. Rowling's first novel, Harry Potter and the Philosopher's Stone, was published in Britain on June 26, 1997.Since then, it has sold more than 450 million copies worldwide and has been translated into 79 languages. The books' magical world has inspired multiple films, spinoffs, memorabilia and amusement park attractions. The White Elephant Cafe, …