[FEATURE] Traffic Junction Mava wrapper + example

[mmorris44]

Feature

Write a wrapper for Mava Traffic Junction. Create an example with IPPO and the wrapper.

Proposal

Wrapper should be based on debugging environment wrapper, but instead wrap the new Traffic Junction environment. Example based off the debugging example, but on Traffic Junction instead.

Definition of done

Example should run without issue. IPPO should not be able to solve the environment.

Mandatory checklist before making a PR

• [ ] The success criteria laid down in “Definition of done” are met.
• [ ] Code is documented - docstrings for methods and classes, static types for arguments.
• [ ] Code is tested - unit, integration and/or functional tests are added.
• [ ] Documentation is updated - README, CONTRIBUTING, or other documentation.
• [ ] All functional tests are green.
• [ ] Link experiment/benchmarking after implementation (optional).