SPRINGFIELD — It’s been nearly a decade since the nation’s top court struck down a Washington, D.C., gun ban and kicked off a wave of pro-firearms changes.But courts across the country are still grappling with the implications. And one of the latest in that line of rulings is expected from the Illinois Supreme Court this week.The justices are slated to decide Thursday on the validity of evidence obtained after a man was arrested for violating an Illinois gun law — one that it ultimately deemed …