An appeals court last week gave a class-action suit against Allstate Insurance Co. some extra muscle.The 5th District Appellate Court ruled claims about the company’s car insurance rates can be adjudicated in the courts and do not have to go through the state’s Insurance Department first.A trio of plaintiffs argue the company is violating consumer fraud and deceptive business laws by charging longtime customers higher premiums than new customers with similar risk factors because the former group is less …