A Phase 3, Prospective, Randomized, Controlled, Open-label, Multicenter, 2-period Crossover Study With a Single Arm Continuation Evaluating the Safety and Efficacy of BAX 930 (rADAMTS13) in the Prophylactic and On-demand Treatment of Participants With Severe Congenital Thrombotic Thrombocytopenic Purpura (cTTP) (Upshaw-Schulman Syndrome) - ICH GCP - Clinical Trials Registry