By BRIAN MAHONEY AP Basketball Writer NEW YORK (AP) — In a record sale for a U.S. sports franchise, the co-founder of Alibaba agreed to buy the remaining 51 percent of the Brooklyn Nets and Barclays Center for about $3.4 billion, two people with knowledge of the details said Friday. Joe Tsai already had purchased 49 percent of the team from Russian billionaire Mikhail Prokhorov in 2018, with the…