ST. LOUIS — The Blues had gone the entire season losing three consecutive home games only once. They picked the wrong time to make it twice — the time that ends your season. But that’s what happened Friday at Enterprise Center. The Colorado Avalanche, Stanley Cup favorites since before the first puck was even dropped in training camp, moved on to the Western Conference finals for the first time since 2002. They turned the lights out on the Blues’ season with a 3-2 victory, thus clinching the second-round playoff series four games to two. Darren Helm, with his first goal of the postseason, scor…