By Priyamvada C (Reuters) - Demand for travel insurance in the United States is set to jump this year, as more Americans turn cautious after a spike in flight cancellations and lost luggage in the last two months upended holiday plans of tens of thousands across the country. Cancellations jumped 73% to 210,503 flights in 2022 from a year earlier, as per flight tracking website FlightAware, largely due to adverse weather and network outage. Led by Southwest Airlines, the nation's carriers...