As rescue workers continued to search yesterday for survivors in the smoking wreckage of the World Trade Center and the Pentagon, representatives of American Airlines and United Airlines began lobbying Congress to restrict lawsuits seeking compensation. In written and oral presentations to the Senate and House Commerce Committees, representatives of the airlines asked for legislation that would limit their financial responsibility to only the passengers and crew of the three planes that crashed in New York and Washington and an aircraft that plowed into a field in Pennsylvania.