Missing fields in CloudEvent deserialisation

Raising this on behalf of a colleague who is on vacation

---

I have started using DAPR pub/sub and am creating a Subscription in a Springboot application, so I am using the JAVA sdk.

The subscriber receives the messages correctly, but I noticed that the CloudEvent class, used to deserialize the incoming event, is missing these fields `tracid`,`traceparent`,`tracestate`,`topic`,`pubsubname`.

I'm using these libraries

implementation 'io.dapr:dapr-sdk:1.5.0'
implementation 'io.dapr:dapr-sdk-actors:1.5.0'
implementation 'io.dapr:dapr-sdk-springboot:1.5.0'

I know that the last version is 1.6.0, but from the javadoc I saw that the CloudEvent class of that version miss the fields too.

cc @fvitolo