"It is well established that the Court has jurisdiction under Part 26 CA 2006 to sanction a scheme which includes a mechanism … under which scheme creditors are required to release claims against third parties where such a release is necessary in order to give effect to the arrangement between the company and the scheme creditors. That test is most clearly satisfied where the scheme compromises debts which are guaranteed and where, absent such a release, pursuit of the guarantor by a scheme creditor would undermine the compromise between the creditor and the company."