[Proposal] Add MoveActionWrapper

[younik]

Description

Whenever I work with Minigrid with full observability, I find the action space more complicated than should be. I believe the action space makes sense for agent view observation, but not with full observability, where using the directions (like FrozenLake) is easier.

As I already coded it for myself, I find it easier to open a PR than an issue but feel free to close it if you believe it is not a common use case.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes