Use GasEstimated for block building
Update ReapMaxBytesMaxGas to include estimated gas (#263)
* checkpoint: add gasEstimate to WrappedTx in mempool
* updated proto with gas estimated + build blocks with gas used + mempool tests
* fix replay stub
* implement fallback to gasWanted if gasEstimate is not set
* remove print
* fix some tests
* fix some tests
* fix nondeterministic test
* remove both maxGasWanted and maxGasEstimated, just use maxGas
* fix test: mempool mocks
* fix race: pending tx mempool size bytes