WASHINGTON (Reuters) - A U.S. judge refused on Thursday to fast-track a congressional lawsuit seeking to force disclosure of President Donald Trump’s federal tax returns, saying it was a complicated and important matter that should not be rushed. U.S. District Judge Trevor McFadden in Washington said in a written order that under U.S. law, there was “only a narrow set of cases that must skip to the front of the line,” and that the House of Representatives Ways and Means Committee had not shown its lawsuit was one of them. McFadden said that while he was not prejudging the case,...