* eth-client API to get transaction in block.
* Job queue to process tracing requests.
* Request traces from job queue runner.
* Max trace completion lag time config for downstream events.
* Maintain cache of previous address resolution.
* Indent using tabs in call_address_tracker to keep diffs sane.
* Undo aggressive falsifying of potential addresses.
* Capture opcode from prev step, more mainnet tx traces.