Test generic binding support via SignalR

[elprans]

As a continuation of #66 and #409, add tests for SignalR and Table Storage bindings.

[pragnagopa]

updated the title to reflect singnalR only. Testing table storage should be trivial. PR #409 should include E2E test for table storage bindings

[anirudhgarg]

This is dependent on #409

[maiqbal11]

@anthonychu already wrote a cool article highlighting this functionality: https://dev.to/azure/end-to-end-serverless-real-time-iot-with-python-4i2b 😄