An action-packed primetime doubleheader of world title fights, headlined by the explosive, eagerly-awaited clash between welterweight champion Keith “One Time” Thurman and former champion “Showtime” Shawn Porter,will come to Barclays Center in Brooklyn on Saturday, June 25. Thurman (26-0, 22 KOs), of Clearwater, Fla., and Porter (26-1-1, 16 KOs), of