NEW YORK (Reuters) - U.S. stocks gained ground on Monday at the onset of a heavy earnings week, while European shares inched higher as investors took heart from potential progress in U.S.-China trade talks and increasing geopolitical tensions sent oil prices climbing.Tech pushed Wall Street into positive territory as investors girded themselves for a week of second-quarter results from major industrial and technology companies and eyed the U.S. Federal Reserve's expected interest rate cut at the..