Provide the capability to add Azure Service Bus plug-ins to the message pump

[stijnmoreels]

Is your feature request related to a problem? Please describe.
Currently, the new Azure SDK doesn't support Azure Service Bus plug-ins so our updated message pump also can't support this.

Describe the solution you'd like
Once this is supported, we should update our message pump.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
PR with new Azure SDK #175
Azure SDK migration guide

[stijnmoreels]

The new Azure SDK does not allow plug-ins but do allow overridden functionality for the ServiceBusSender/ServiceBusReceiver (docs) but we will have to investigate if we want to allow this extensibility. We could use an injected Azure client instead of creating them ourselves, though.