United Airlines made a huge splash this week by announcing 10 all-new destinations as part of the carrier's largest international expansion ever.But the airline isn't just adding new routes for 2027.It's also bringing back every one of the ultra-unique destinations it flew this summer, from southern Europe to the Arctic.United's epic flight to Greenland? "We are planning to be back," chief network planner Patrick Quayle confirmed this week.Ditto…