Problem: coinbase should not be the current one in traceTransaction execution

[yihuang]

System info: ethermint main

Steps to reproduce:

In EVMConfig, the coinbase address is always fetched based on current context ctx.BlockHeader().ProposerAddress, which will be the current check state, aka. the last committed block's proposer address, in grpc-only mode, it would be an empty one.
But in traceTransaction, or eth_call with historical height, it should be the proposer of respective block.

Expected behavior: coinbase should be the correct one when executing historical transactions.

Actual behavior: is either the latest one or empty.

Additional info:

Solution: find the proposer address in json-rpc through tendermint api, and pass explicitly to grpc query handler.

[VictorTrustyDev]

Will also resolve this #1269

[yihuang]

Will also resolve this #1269

yeah, I guess this is the root cause of that.