(Reuters) - Forever 21's new co-owner Authentic Brands Group said on Tuesday it had appointed former H&M executive Daniel Kulle as the new chief executive officer of the bankrupt apparel retailer.Kulle, a two-decade veteran at the Swedish apparel retailer, most recently worked as strategic adviser to former H&M Group Chief Executive Karl-Johan Persson. Authentic Brands said earlier this month it had partnered with mall owner Simon Property and Brookfield Property to acquire Forever 21, without..