Test reorganization and some additional checks for integrity of created MinariStorage instances

[balisujohn]

Description

• Reorganizes the tests to reflect the directory structure of the module like in Gymnasium. *
• Adds the helper function _check_data_integrity() to test_dataset_creation.py which makes sure a MinariStorage has actions consistent with its action space and observation consistent with its observation space, and makes sure there are the right number of episodes and they are the right length. _check_data_integrity() is added to the tests test_generate_dataset_with_external_buffer and test_generate_dataset_with_collector_env along with a few consistency checks on the MinariDatasetclass generated in each test.

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• I have run pytest -v and no errors are present.
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I solved any possible warnings that pytest -v has generated that are related to my code to the best of my knowledge.
• 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

[elliottower]

To fix the pre-commit issues, try setting pyright hard coded to this version: [email protected]
(full file example:
https://github.com/elliottower/Shimmy/blob/37b1d4c81632e941a1f485d2421ccf7845b55211/.pre-commit-config.yaml)

[younik]

LGTM