This PR refactors the structlog a bit, making it so that it can be used
in a streaming mode.
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OBS: this PR makes a change in the input `config` config, the third
input-parem field to `debug.traceCall`. Previously, seteting it to e.g.
` {"enableMemory": true, "limit": 1024}` would mean that the response
was limited to `1024` items. Since an 'item' may include both memory and
storage, the actual size of the response was undertermined.
After this change, the response will be limited to `1024` __`bytes`__
(or thereabouts).
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The commandline usage of structlog now uses the streaming mode, leaving
the non-streaming mode of operation for the eth_Call.
There are two benefits of streaming mode
1. Not have to maintain a long list of operations,
2. Not have to duplicate / n-plicate data, e.g. memory / stack /
returndata so that each entry has their own private slice.
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Co-authored-by: Gary Rong <garyrong0905@gmail.com>
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