Update validateFormat for ccm

[ishantiw]

Description

• Updated crossChainMessage schema
• Update validateFormat function for ccm according to LIP0049

def validateFormat(ccm: CCM) -> None:
    # Try to encode ccm.
    # This raises an error if the ccm does not follow the correct schema.
    ccmBytes = encode(crossChainMessageSchema, ccm)
    # ccm.module must be an alphanumeric string.
    if not re.match("^[a-zA-Z0-9]*$", ccm.module):
        raise Exception("Cross-chain message module name must be alphanumeric.")
    # ccm.module must be an alphanumeric string.
    if not re.match("^[a-zA-Z0-9]*$", ccm.crossChainCommand):
        raise Exception("Cross-chain message command name must be alphanumeric.")
    # Check ccm size.
    if ccmBytes > MAX_CCM_SIZE:
        raise Exception(f"Cross-chain message size is larger than {MAX_CCM_SIZE}.")

Acceptance Criteria

• Update and add unit test cases for validateFormat

Additional Information

Related LIP PR update LiskArchive/lips#148