Summary

(lifted from PR description)

This PR primarily does three things:

• ensures that the message stream is always destroyed and ensure that the socket is always destroyed
• consolidate the connection clean up logic into a single function that is called from each point where the connection is cleaned out
• improves the unit tests to properly assert on the state of the connection after _cleanup has been called.
  • Additionally, the unit tests now in for synchronous versus asynchronous behavior for the various error and clean up scenarios.