HiTL BO tutorial - Integrate BO with MongoDB instead of relying solely on a locally stored `save_to_json_file`

[sgbaird]

See #344 (comment) and parent issue.

Related to JSON loading/reloading: https://colab.research.google.com/drive/1A2p1oUSsD8Edlu2haaB-FBSSjim3HTLS?usp=sharing

Success measure is that someone can kill the kernel, restart it, and it can pick back up from where it left off.