DETROIT — The Flyers say they are moving forward. Two days after goalie Carter Hart requested an indefinite leave of absence, the team is confident that backup Sam Ersson can carry the workload. And why shouldn’t it be? Ersson has been stellar since Nov. 1. Since that date, he ranks tied for second in goals-against average (2.09) and fourth in save percentage (.919) among goalies who have played a minimum of 20 games. In December, he started five straight games and went 3-1-1 with a 2.16 GAA and a .921 save percentage. That stretch included a 1-0 win against the Detroit Red Wings. It’s a far c…