Support cloud events in schema

[thompson-tomo]

Summary I want to have a top level of object CloudEvent, which records information about the cloud event.

Motivation: My application produce & consume cloud events and as such it would be useful to capture information about these events in a consistent manner.

Detailed Design: The properties for the new top level property should consist of the following which is a one to one mapping for the event.

• specversion e.g. 1.0.0
• type e.g. com.github.pull_request.opened"
• source e.g. https://github.com/cloudevents/spec/pull
• subject e.g. 123
• id e.g. A234-1234-1234
• time e.g. 2018-04-05T17:31:00Z
• datacontenttype e.g. text/xml
• Action e.g. Send, Recieve
• Transport e.g. NATS, AMQP

[thompson-tomo]

Closing as handled via open telemetry.