use helper functions that accept node config, instead of passing each parameter

[potehinre]

https://github.com/GenesisKernel/genesis-tests/blob/6f57ca7ef9dc460cf469ac3643267cc076480d3f/cost_tests.py#L27

        result = utils.call_node_contract(conf["1"],
                                     "NewContract", data, tokenCreater)
        status = utils.node_txstatus(conf["1"],
                                result['hash'], tokenCreater)
        commisionWallet = utils.get_commission_wallet(conf["1"], 1)