fix(fw): Fix FixedSizeBytes != comparison

[marioevz]

🗒️ Description

Before this PR, it was possible that both of these statements returned true:

Address(0x100) == "0x100"
Address(0x100) != "0x100"

Reason was that, since __ne__ was not implemented for FixedSizeBytes and the fallback was to use str compare.

🔗 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.

[spencer-tb]

LGTM - Nice catch!