[Pyamqp] Investigate coordination of receive task and client call back

[kashifkhan]

Today we are using two concurrently running background tasks to do the follow

• Receive messages from EH or SB and populate a buffer
• Callback task that reads from the buffer and calls the user defined function

The coordination between these two can lead to some odd behaviors in exception state, locks esp as the number of partitions increase. There is a patch today that address this issue.

We want to see how to effectively re-design this flow so that avoid this

• Look at implementing a linear flow similar to whats in uamqp
• Perf difference with changes
• Exception story after changes

[azure-sdk]

Label prediction was below confidence level 0.6 for Model:ServiceLabels: 'Azure.Core:0.3959683,Service Bus:0.22461891,Storage:0.14262989'