The Tampa Bay Lightning are keeping one of their breakout players around for the long haul. Defenceman J.J. Moser has signed an eight-year, $54 million extension to stay in Tampa, the team announced Saturday. The deal is worth $6.75 million in average annual value. Moser is in the midst of an impressive second season with the Lightning, registering three goals and nine assists through 34 games. He leads the team in average ice time at 21:43 and plus-minus at plus-24. His plus-minus ranks sixth in the NHL heading into Saturday’s action. Since being drafted 60th overall by the Arizona Coyotes…