SPRINGFIELD — Targeting what they call Illinois’ “underground economy,” legislators have signed off on new powers for the state’s top lawyer to investigate and intervene in labor cases.The General Assembly last week approved Senate Bill 193, allowing the attorney general’s office to file lawsuits and enforce provisions of the Minimum Wage Act, the Prevailing Wage Act and other laws, without first getting a referral from the Department of Labor.The idea targets businesses who try to cut …