WASHINGTON — The Justice Department sued Walmart on Tuesday, accusing it of fueling the nation’s opioid crisis by pressuring its pharmacies to fill even potentially suspicious prescriptions for the powerful painkillers.The civil complaint filed points to the role Walmart’s pharmacies may have played in the crisis by filling opioid prescriptions and Walmart’s own responsibility for the allegedly illegal distribution of controlled substances to the pharmacies at the height of the opioid crisis …