By Sarah N. Lynch WASHINGTON (Reuters) -Steve Bannon, a key associate of former President Donald Trump and an influential figure on the American right, was convicted on Friday of contempt of Congress for defying a subpoena from the committee investigating last year’s attack on the U.S. Capitol, a major victory for the Democratic-led panel. A jury found Bannon, 68, guilty of two misdemeanor counts for refusing to provide testimony or documents to the House of Representatives select committee as it scrutinizes the Jan. 6, 2021, rampage by Trump supporters who tried to upend the results of the 20…