chore(fw): add chain id to all fixtures

[spencer-tb]

🗒️ Description

Adds the chain_id as a field for all fixture types. Set to 1 by default unless overwritten in the state/blockchain test environment.

Blockchain/Engine Test Example Json

{
    "tests/shanghai/eip3855_push0/test_push0.py::test_push0_contracts[fork_Shanghai-blockchain_test]": {
        "network": "Shanghai",
        "chainId": "0x01",  # root of the test fixture
        ...

State Test Example Json

{
    "tests/shanghai/eip3855_push0/test_push0.py::test_push0_contracts[fork_Shanghai-state_test]": {
        "chainId": "0x01",  # within the state test env
        "env": {
            "currentCoinbase": "0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba",
            ...

🔗 Related Issues

N/A

✅ 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.

[marioevz]

Thanks, some comments.

[winsvega]

So when generating a test with chain_id will all the transactions be of that same chain_id ?
Also we should allow to have tx with different chain id for test purposes