This change is fixing our docker file which is used to build our harness code image used for PR deployments.
Furthermore, the change contains some logging improvements that were added along the way of setting up the PR environment.
This change introduces the concept of a principal (abstraction of call identity), and adds a new service account type principal. Also adds support for different tokens (session, PAT, SAT, OAuth2) and adds auth.Session which is being used to capture information about the caller and call method.