LOS ANGELES — Shares of Netflix jumped in extended trading Tuesday after the company reported adding 13.1 million subscribers during the fourth quarter, stronger growth than Wall Street expected as the streamer builds its ad-supported service and cracks down on password sharing.Netflix now has 260.8 million paid subscribers, a new record for the service.The subscriber growth easily tops the 8.76 million paid membership adds Netflix reported in the third quarter. The company also blew past Wall S...