PARIS — Italy, Saudi Arabia and South Korea are battling it out in Paris on Tuesday for the right to host the Expo 2030 world fair, a five-yearly event that attracts millions of visitors and billions of dollars in investment. The three countries’ delegations have been in horse-trading overdrive over the past few months to win votes from the 182 member states of the Bureau International des Expositions, holding splashy lobbying events in the French...