add checkpointStrategy parameter to event-hub

[christle]

Signed-off-by: Christian Leinweber [email protected]

[tomkerkhove]

What do you think @zroubalik ?

[zroubalik]

Generally looking good, I have added a minor corrections wrt formatting.
And I'd reformat the checkpointStrategy options to start with lowercase, so it is consistent with the rest of the spec.

[christle]

I've add more details to the parameter list.

additionally i found out there are also 2 implementations for C#. I have tested both, and the behavior is like Python and Java. One Implementation based on the EventProcessorHost and a new one, which is called EventProcessorClient. The EventProcessorHost works with the default path(no checkpointStrategy specified), the EventProcessorClient with the blobMetadata strategy (which is great, i think). Microsoft called the EventProcessorHost implementation "legacy" (see: https://docs.microsoft.com/de-de/azure/event-hubs/event-hubs-dotnet-standard-get-started-send-legacy).

[tomkerkhove]

LGTM, just a few tweaks!

[tomkerkhove]

Thank you!