Rex Heuermann’s kids are “along for the dark ride” and standing by the suspected Gilgo Beach serial killer, according to their lawyer. Victoria Heuermann and Christopher Sheridan remain by their dad’s side even after he was charged with two more murders and prosecutors detailed a sickening “planning document” he allegedly kept on a computer in his Massapequa Park home, lawyer Vess Mitev said. “They continue to bravely face the scrutiny and adversity head-on and they will wait for the legal process to conclude in a courtroom and not in the court of public opinion,” Mitev told The Post on Friday...