* Remove unnecesary await
* Implement gas calculation for NON-GETH nodes
* Add tests
* Refactor estimateSafeTxGas: now getGasEstimationTxResponse calculates gas or throws errors based on the current node
* Refactor getOpenEthereumErrorDataResult to make it works with Nethermind
Updates tests
Co-authored-by: Daniel Sanchez <daniel.sanchez@gnosis.pm>