Chemotherapy, Immunotherapy, RadiationSATURN-STS: Phase II Study of Neoadjuvant Atezolizumab With Doxorubicin, Concurrent Atezolizumab With Pre-operative Radiation Therapy and Adjuvant Atezolizumab in Patients With High-risk Surgically Resectable Extremity and Truncal Soft Tissue Sarcoma