l2r packaging

[hermgerm29]

This is a long-overdue overhaul of the repository to prepare l2r for Python packaging and publishing on PyPi. The main features include:

• Modifying the structure of the repository to be more package friendly
• Refactor of the package to be more testable and easier to understand
• Added a handful of unit tests
• Added a handful of integration tests with the simulator
• Added CI workflows for unit tests and lint checks
• Added multiple examples on how to use the environment
• Added makefile to make contributing easier

The refactor isn't complete and coverage is not satisfactory, but these changes make the repository more understandable, extendable, and more friendly to other contributors.

[hermgerm29]

I'll go ahead and complete the one-container example before considering this done