Message format according to monitoring service spec

def to_dict(self) -> Dict[str, Any]:
        """Message format according to monitoring service spec"""
        return {
            'type': self.__class__.__name__,
            'channel_identifier': self.channel_identifier,
            'token_network_address': to_normalized_address(self.token_network_address),
            'balance_hash': encode_hex(self.balance_hash),
            'nonce': self.nonce,
            'additional_hash': encode_hex(self.additional_hash),
            'signature': encode_hex(self.signature),
            'chain_id': self.chain_id,
        }