CBS News will launch CBSN: On Assignment next month, a new primetime summer series featuring what the network is calling “experiential reports” from around the world by more than a dozen CBS correspondents. The broadcast kicks off Monday July 31 at 10 pm ET/PT on both CBS and CBSN, the network's 24/7 streaming service. The new series will air on four consecutive Mondays and feature what CBS calls the streaming service’s “distinctive storytelling style.” Each hour-long…