fix(fw): EOF - Accept initcode_prefix on EOF Container.Init

[marioevz]

🗒️ Description

Adds initcode_prefix parameter to Container.Init in order to add executable bytecode that must be appended before EOFCREATE[0](0, 0) in the resulting container's code section.

🔗 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: A PR with removal of converted JSON/YML tests from ethereum/tests have been opened.
• 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.

[winsvega]

And what will it look like if we mstore some bytes in init code prefix?

[marioevz]

And what will it look like if we mstore some bytes in init code prefix?

Not really, it will just append bytecode to execute before returning the contract, for example an SSTORE if you would like to store something during contract initialization.