Automated interoperability demo

[m00sey]

Currently interoperability validation is done manually by approximating logging output from demo.

To support interop efforts moving forward @pfeairheller suggested using a serialization of the KEL as an output from the demo would allow for automated running of demos.

As serialization is yet to be fully implemented in any KERI library this issue would update the current kerigo demos to marshal the KEL to JSON and then BASE64 encode the value, then introduce a GHA workflow to run the demos and assert the correctness of the "serialized KEL".

Eventually we would replace this brute force method with true serialization, and expand to other repositories.