CloudEvent should magically recognize dict's from known services

[rakshith91]

While the current implementation of the from_dict in cloud event is round trippable, the from_dict does not work with known services.

In other words, this should not break:

with event_hub_client:
    with receiver:
        for msg in receiver:
            batch = event_hub_client.create_batch()
            batch.add(EventData(f"Receiving messages..."))
            event = CloudEvent.from_dict(
                json.loads(str(msg))
            )

[jongio]

I would like to see us create something more intuitive than this:

event = CloudEvent.from_dict(
                json.loads(str(msg))
            )

Something like this:

event = CloudEvent.from_str(msg)

azsdke2e
azsdke2e2

[lmazuel]

Start with a methid like:

def gimme_bytes(o : Union[SBMessage, EHMessage, QueueMessage]) -> bytes:
   ...

You can't import any SDKs, since you're inside azure core (duck typing)