chore: IDSSE-441: PublishConfirm internal cleanup

[mackenzie-grimes-noaa]

Linear Issue

• IDSSE-423 - handle null connection/channel
• IDSSE-441 - consolidate pass-through methods

Changes

• Consolidate small methods that only exist to be called one time by another method.
• Add None-check around any usage of self._connection or self._channel
  • They can technically be None, but they never should be after connection/channel is initialized
  • When possible, use the connection arg that pika passes to our callbacks to avoid using the private variable at all.
• Block attempts to call PublishConfirm.start() more than once
  • This is same behavior as calling Python Thread.start() twice

Also a minor addition to rabbitmq_utils:

• Added a connection_parameters property to Conn data object.
  • This property can be passed as parameters to any type of pika connection, and is less limited than Conn.to_connection() which is only useful for making a BlockingConnection.

[Geary-Layne]

Nice clean up

[Geary-Layne]

Nice