Add support for CloudEvents v1.0.2

[Gunni]

Expected Behavior

Able to use proto_data, somehow.

Actual Behavior

No code in repo even refers to proto or any way to use it because v1.0 did not have that.

Steps to Reproduce the Problem

1. Make a proto for your data
2. Try to assign it to data
3. Fail / Object of type X is not JSON serializable

Specifications

• Platform: Fedora Linux 36 (Workstation Edition)
• Python Version: 3.10.7

[xSAVIKx]

Hello @Gunni and thank you for opening this. Indeed, the SDK does not support proto format at the moment. PRs are very welcome 🙂

I plan to start working on this, but don't know when exactly yet