TORONTO — Mitch Marner and the Maple Leafs were cruising. The winger had bagged his second-career hat trick to snap a long goal drought and help his team build a 3-1 advantage through two periods. All Toronto had to do was lock things down over the final 20 minutes. A familiar storyline then bubbled to the surface, setting the stage for Marner to leave a final mark on the night — after his goaltender held the fort. Marner buried the shootout winner on the heels of emphatically halting an eight-g