By Howard Schneider WASHINGTON (Reuters) -Federal Reserve officials are preparing to gather on Tuesday for a two-day meeting amid rising concerns about the central bank's independence and uncertainty about the composition of its policy-setting committee, as President Donald Trump pushes ahead with a rushed effort to overhaul a pillar of the U.S. economy. A federal appeals court is expected to rule on Monday on whether Fed Governor Lisa Cook can continue in her job while litigation over Trump's attempt to ...