EIP-4844: Implement SignedBlobTransaction and validation

[jangko]

Besides add new fields to Transaction type, accompanying ssz encode and decode must be implemented.
They should be implemented in nim-eth.

then additional validation must be added:
tx.payload.len <= MAX_CALLDATA_SIZE = 2 ** 24
tx.accessList.len <= MAX_ACCESS_LIST_SIZE = 2 ** 24
tx.accessList[n].storageKeys.len <= MAX_ACCESS_LIST_STORAGE_KEYS = 2 ** 24
tx.blobVersionedHashes.len <= MAX_VERSIONED_HASHES_LIST_SIZE = 2 ** 24

The signature is verified and tx.origin is calculated as follows:

def unsigned_tx_hash(tx: SignedBlobTransaction) -> Bytes32:
    # The pre-image is prefixed with the transaction-type to avoid hash collisions with other tx hashers and types
    return keccak256(BLOB_TX_TYPE + ssz.serialize(tx.message))

def get_origin(tx: SignedBlobTransaction) -> Address:
    sig = tx.signature
    # v = int(y_parity) + 27, same as EIP-1559
    return ecrecover(unsigned_tx_hash(tx), int(sig.y_parity)+27, sig.r, sig.s)

The hash of a signed blob transaction should be computed as:

def signed_tx_hash(tx: SignedBlobTransaction) -> Bytes32:
    return keccak256(BLOB_TX_TYPE + ssz.serialize(tx))