A DECADE AGO Jordan Bardella was a mere teenager, spending hours after school firing at enemy combatants on “Call of Duty” video games. Today the 28-year-old leader of the hard-right National Rally may be weeks away from becoming prime minister of France, and its youngest ever by a long way. After a two-round legislative election on June 30th and July 7th, his party could win enough seats to form a government. The ascent of Marine Le…