Kroger sued the Federal Trade Commission on Monday, seeking to block the regulator from reviewing the grocery chain’s proposed $25 billion merger with smaller rival Albertsons in its in-house tribunal.Kroger called the tribunal unconstitutional, saying the matter should be resolved in a federal court.The lawsuit filed in Cincinnati comes a week before the company is scheduled to face a trial where the FTC has asked a federal judge in Portland, Ore., to temporarily block the merger while its in-house judges ...