feat: port entry points to click cli; add tests

[danceratopz]

🗒️ Description

• Ports the scripts previously defined in src/entry_points to click and moves them to src/cli.
• Adds tests for the order_fixtures and fill click commands.

If working in an existing EEST installation a reinstall is necessary:

pip install --force-reinstall -e .

🔗 Related Issues

None

✅ Checklist

• All: Set appropriate labels for the changes.
• All: Considered squashing commits to improve commit history.
• All: Added an entry to CHANGELOG.md.
• All: Considered updating the online docs in the ./docs/ directory.
• Tests: All converted JSON/YML tests from ethereum/tests have been added to converted-ethereum-tests.txt.
• Tests: Included the type and version of evm t8n tool used to locally execute test cases: e.g., ref with commit hash or geth 1.13.1-stable-3f40e65.
• Tests: Ran mkdocs serve locally and verified the auto-generated docs for new tests in the Test Case Reference are correctly formatted.

[marioevz]

Looks awesome, love this library!

Thanks.

[marioevz]

Rebased to the latest main and force pushed.