CallTracer implementation for debug endpoints

[goran-ethernal]

Description

This PR implements the callTracer for debug rpc endpoints. debug_ rpc endpoints config is now expanded with tracer field to specify which tracer you want to be used. Currently, Edge has two tracers: structTracer and callTracer. If no tracer is specified when calling some debug endpoint, structTracer will be used by default.

This implementation is provided by the Gateway.fm friends, who implemented this on their own Edge fork.

How to use callTracer

1. Start Edge nodes.
2. Run this curl to get some epoch ending block:

curl -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"eth_getBlockByNumber", "params": ["10", false]}' http://localhost:10002`

3. After eth_getBlockByNumber returns a result, take some transaction hash from transactions item in json result.
4. Run this curl to get call debug_traceTransaction:

curl -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"debug_traceTransaction", "params": ["transactionHash", {"tracer": "callTracer"}]}' http://localhost:10002

5. Notice that result looks something like this:

{
  "jsonrpc": "2.0",
  "id": null,
  "result": {
    "type": "CALL",
    "from": "0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE",
    "to": "0x0000000000000000000000000000000000000101",
    "value": "0x0",
    "gas": "0xeedd4",
    "gasUsed": "0x13966",
    "input": "0x0f50287c00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000",
    "output": "0x",
    "calls": [
      {
        "type": "DELEGATECALL",
        "from": "0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE",
        "to": "0x0000000000000000000000000000000000000101",
        "value": "0x0",
        "gas": "0xea7be",
        "gasUsed": "0x12eb7",
        "input": "0x0f50287c00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000",
        "output": "0x"
      }
    ]
  }
}

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

[Stefan-Ethernal]

Generally LGTM