Clarify OpAMP communication pattern assumptions

[djaglowski]

It may be helpful or necessary to articulate some of the basic aspects of OpAMP's communication patterns.

• Is the protocol synchronous or asynchronous?
• Can either party originate requests?
• Are there any generalized behaviors for communication error cases?
  • What happens if a request is sent but the websocket is closed before a response is received?
  • What happens if a request is sent but no response is received?
  • What happens if a request is sent multiple (many) times without apparent regard for the result?

Probably some of these questions are obvious, implicit in the nuances, or currently undefined. However, as a reader of the spec, it would be helpful to establish any broad rules or assumptions.

[tigrannajaryan]

All good questions. I agree these need to be clarified.