LOS ANGELES — Literally speaking, the Padres did not have to win Wednesday night. But they had to win. And they did, in the kind of back and forth, back and forth, back and forth thriller that makes the postseason a mental grind and churns every internal organ. In the end, the Padres’ 5-3 victory over the Dodgers in Game 2 of the National League Division Series at Dodger Stadium sent the series to Petco Park with the teams tied at a game apiece. Game 3 is scheduled for 5:37 p.m. Friday with Game 4 at 6:37 p.m. Saturday. An unlikely climb would have been required had the Padres lost. Major Leag…