BeginTx: spec for contract creation via Tx

[ed255]

Recently we merged the spec for CREATE/CREATE2: #355
But I noticed that the spec for contract creation via Tx is not done:

zkevm-specs/src/zkevm_specs/evm_circuit/execution/begin_tx.py

Lines 91 to 97 in 29f1c2d

	if tx_is_create == 1:
	# TODO: Verify created address
	# code_hash represents the contract creation code
	# 1. In the case of root call, code_hash is the hash of the tx calldata.
	# 2. In the case of internal call, code_hash is the hash of the chunk of
	# caller memory corresponding to the contract init code.
	raise NotImplementedError

Nevertheless on the circuit side this seems to be implemented:
https://github.com/privacy-scaling-explorations/zkevm-circuits/blob/0e1d230191d3a1b3ea4b27034c73a545a6e66158/zkevm-circuits/src/evm_circuit/execution/begin_tx.rs#L212-L295

So we need to sync the specs on the create case of BeginTx.