KDVR-Channel 31, Denver’s Fox affiliate, may soon return to its namesake parent instead of becoming a unit of Sinclair Broadcast Group, pending approval from federal regulators. The sale of KDVR and 22 other stations, announced Tuesday by Sinclair as a way of easing FCC and Justice Department worries about media concentration, would only happen after Sinclair’s proposed $3.9 billion merger with Tribune Media is approved.