Add expire_conn for service bus connection failures

[erewok]

In a recent PR (#1), we expired Eventhub connections from the ManagedEventhubProducer if there were connection issues using those connections. At the time, we noted that this work should also be applied for the ServiceBusSender connections as well in that Managed client.

This PR includes the call to the ConnectionPool.expire_conn method when any of the following exceptions are thrown while trying to schedule a message with the connection:

• ServiceBusCommunicationError
• ServiceBusAuthorizationError
• ServiceBusAuthenticationError
• ServiceBusConnectionError

All of the above imported from azure.servicebus.exceptions.

It's possible in the future that we will want to amend the list of exceptions that can cause us to expire connections: from reading the docstrings on the exceptions in this module, it seemed like some of the others could also apply. For now, we're using the above.

This test also improves test coverage for the service_bus module, including new tests for the ManagedAzureServiceBusSender class (no tests covered this class previously).

[github-actions]

Package	Line Rate	Health
.	90%	✔
clients	88%	✔
testing_utils	76%	❌
Summary	86% (851 / 984)	✔