Hotfix: add check to geth traces for missing output

[charlielewisme]

Check for errors where node response is missing output fields. Use similar retry mechanism to existing check for responses with null result.

The issue we encountered is probably related to: maticnetwork/bor#763

Also:

• update the test_export_geth_traces.py mock test data
• use expected Polygon values to make test more realistic
• required to prevent the new check raising errors

---

The basis for the check is the bad data I found in the geth_traces_00.json of a failed run. This source file is now overwritten, but here's the line I cut from it, a single block (which I've then formatted for readability):
bad_geth_trace.txt

I've inferred (from export_geth_traces_job.py) that the bad response would have been:
bad_response_full.txt

{
  "jsonrpc": "2.0",
  "method": "debug_traceBlockByNumber",
  "params": [
    "0x2698501",
    {
      "tracer": "callTracer",
      "timeout": "120s"
      
    }
  ],
  "id": 40469761
}

{
  "jsonrpc": "2.0",
  "id": 40469761,
  "result": [
    {
      ...
    }
​
    ...
    
    {
      "result": {
        "type": "CREATE",
        "from": "0x6443fdb921b5e97e56ce68f17e136173e34022c9",
        "to": "0xc041db08566c3051ae0d7acb2fc9b929ddce155c",
        "value": "0x0",
        "gas": "0x8d709",
        "gasUsed": "0x6cd1c",
        "input": "0x60806040526040516 ... ... 000",
        "calls": [
          ...
        ]
      }
    },
​
    ...
​
    {
      ...
    }
  ]
}

I noted that traces with returned error field do also not have output, hence why I excluded these, see this genuine RPC response for block_with_error