SPRINGFIELD — A Sangamon County judge this week sealed the case file for a search warrant seeking information about alleged sexual harassment and stalking claims against former state Rep. Jack D. Franks.The warrant, which was executed Jan. 29 at Illinois House Speaker Michael J. Madigan’s office, was first reported by the Chicago Sun-Times on Jan. 31.The search by the Illinois State Police was justified because “probable cause exists for the crimes of criminal sexual abuse, criminal sexual assault …