Add pydantic to parse incoming events

[elmsdata]

@erkist outlined, the next enhancement to the Python SDK would be to parse incoming events! Like in the CloudEvents Python SDK, they use Pydantic used for data parsing and validation. Issue is to track changes (for future changelog), conversations outside the pull request and any other feedback/input from the community!

[AshitaSingamsetty]

I would like to work on this and will raise a PR.

[AshitaSingamsetty]

I would like to work on this and will raise a PR.

[elmsdata]

I would like to work on this and will raise a PR.

Thanks Ashita for taking up this request, let me know if I can help with anything!