JCOG1019: An Open-label, Non-inferiority, Randomised Phase 3 Study Comparing the Effectiveness of Watchful Waiting (WW) and Intravesical Bacillus Calmette-Guérin (BCG) in Patients (Pts) with High-grade pT1 (HGT1) Bladder Cancer with pT0 on the 2nd Transurethral Resection (TUR) Specimen