Logic to compute fees for data blobs as well as additional check that
verifies if user was willing to pay the current `data_gas` price.
Updated `FakeExponential` function to work with uint256.
types.NewMessage now expects maxFeePerDataGas param, which will be used
in transaction verification (preCheck). GetPayloadV3 method added to
EngineAPI. Some cosmetic changes applied.
This PR contains very small EIP-4844 additions. GasPool is modified and
now it is a struct with 2 fields "gas" and "dataGas" (blobs are priced
in dataGas). ExcessDataGas block header field added. ExcessDataGas
needed to compute the data gas price. EIP-4844 helper functions are
added as well.