By Lindsay Dunsmuir and Ann Saphir (Reuters) -The Federal Reserve needs to act aggressively to bring down high inflation, and doing so could very well include a half-percentage-point rate hike at its next policy meeting in May, two U.S. central bank policymakers said on Wednesday. “I would like to front-load some of that,” Cleveland Fed President Loretta Mester said on a call with reporters when asked about the path of interest rate increases this year. “I think it’s important that we start moving that rate up and I think that better positions us if we do it earlier rather than later for what …