Issue Description:

The current API contract between the Control Plane and Data Plane has grown organically and is causing us problems e.g MGDOBR-1144

With the introduction of Camel DSL as a Processing language, this is a chance for us to step back and redesign the API that facilitates our Control Plane to Data Plane communication, incorporating the lessons learnt from our experience building v1.

Acceptance Criteria: 

• An ADR specifying the API contract between control plane and data plane including
  • Data structures of the API
  • When callbacks occur from the data plane to the control plane to support the 30 day milestone 

Out of Scope: 

• Implementing the new API. This is a design task.