AVRO-3954: [common-lisp] Add Common Lisp implementation

[SahilKang]

What is the purpose of the change

This integrates https://github.com/SahilKang/cl-avro

Verifying this change

This change adds a new implementation, with its own tests. See the readme in this commit to run tests

Documentation

The API is documented via docstrings, which are discoverable through the normal lisp repl facilities