rpc-compat: show diff when receieved response conflicts with expected

[lightclient]

As suggested by @fjl, I have added a diff view to the error output of the rpc-compat simulator which a conflict arises. It substantially improves the readability -- the mismatch is immediately clear.

Before:

invalid response
want: {"id":3,"jsonrpc":"2.0","result":{"baseFeePerGas":"0x2db08786","difficulty":"0x20000","extraData":"0x","gasLimit":"0x4c4b40","gasUsed":"0x5208","hash":"0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","miner":"0x0000000000000000000000000000000000000000","mixHash":"0xf398615221db789347ea256bcc9d4fe431d520c638b826b55632a2d1fe759f2e","nonce":"0x4b6c6336198f3aff","number":"0x2","parentHash":"0x1bf5e60055636418c90891e234161b63c70b85644a68dcd1570ae1052a64c57c","receiptsRoot":"0x056b23fbba480696b65fe5a59b8f2148a1299103c4f57df839233af2cf4ca2d2","sha3Uncles":"0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347","size":"0x26a","stateRoot":"0x730a6f5dbff0b86dd73ff3f2ba05e0e117129514002c742c716e88ee64426019","timestamp":"0x14","totalDifficulty":"0x40001","transactions":[{"blockHash":"0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5","blockNumber":"0x2","from":"0x658bdf435d810c91414ec09147daa6db62406379","gas":"0x5208","gasPrice":"0x2db08786","hash":"0x01d4a8006d417b25f8339501b42cfde957f85a2c18c604e69939d610933a8fde","input":"0x","nonce":"0x1","r":"0x5d50bd58d78c6bb56bba9f4b28b251c616231e9e35ab9733100c5245b7b469c5","s":"0x5241e473259c43bb38387211fa93ce8d5edf98775a20f971d31192290ca3970","to":"0x658bdf435d810c91414ec09147daa6db62406379","transactionIndex":"0x0","type":"0x0","v":"0x26","value":"0x3e8"}],"transactionsRoot":"0x7ca7896b5edf21a06d64da4ed0e0a8137fc95fa3c0ad4a89d79c194d895e1a40","uncles":[]}}
got:  {"id":3,"jsonrpc":"2.0","result":{"baseFeePerGas":"0x2db08786","difficulty":"0x20000","extraData":"0x","gasLimit":"0x4c4b40","gasUsed":"0x5208","hash":"0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","miner":"0x0000000000000000000000000000000000000000","mixHash":"0xf398615221db789347ea256bcc9d4fe431d520c638b826b55632a2d1fe759f2e","nonce":"0x4b6c6336198f3aff","number":"0x2","parentHash":"0x1bf5e60055636418c90891e234161b63c70b85644a68dcd1570ae1052a64c57c","receiptsRoot":"0x056b23fbba480696b65fe5a59b8f2148a1299103c4f57df839233af2cf4ca2d2","sha3Uncles":"0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347","size":"0x26a","stateRoot":"0x730a6f5dbff0b86dd73ff3f2ba05e0e117129514002c742c716e88ee64426019","timestamp":"0x14","totalDifficulty":"0x40001","transactions":[{"blockHash":"0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5","blockNumber":"0x2","chainId":"0x1","from":"0x658bdf435d810c91414ec09147daa6db62406379","gas":"0x5208","gasPrice":"0x2db08786","hash":"0x01d4a8006d417b25f8339501b42cfde957f85a2c18c604e69939d610933a8fde","input":"0x","nonce":"0x1","publicKey":"0xd9a872707aaec451b19445dd00c5ad619f36a0dcad5b035b03baf16849f719e806455742d05bf26ab4d0e715198709e0e7794c214ccde55731a9fbbd51edf2d8","r":"0x5d50bd58d78c6bb56bba9f4b28b251c616231e9e35ab9733100c5245b7b469c5","raw":"0xf86501842db0878682520894658bdf435d810c91414ec09147daa6db624063798203e88026a05d50bd58d78c6bb56bba9f4b28b251c616231e9e35ab9733100c5245b7b469c5a005241e473259c43bb38387211fa93ce8d5edf98775a20f971d31192290ca3970","s":"0x5241e473259c43bb38387211fa93ce8d5edf98775a20f971d31192290ca3970","to":"0x658bdf435d810c91414ec09147daa6db62406379","transactionIndex":"0x0","type":"0x0","v":"0x26","value":"0x3e8"}],"transactionsRoot":"0x7ca7896b5edf21a06d64da4ed0e0a8137fc95fa3c0ad4a89d79c194d895e1a40","uncles":[]}}

After:

response differs from expected:
 {
   "id": 3,
   "jsonrpc": "2.0",
   "result": {
     "baseFeePerGas": "0x2db08786",
     "difficulty": "0x20000",
     "extraData": "0x",
     "gasLimit": "0x4c4b40",
     "gasUsed": "0x5208",
     "hash": "0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5",
     "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
     "miner": "0x0000000000000000000000000000000000000000",
     "mixHash": "0xf398615221db789347ea256bcc9d4fe431d520c638b826b55632a2d1fe759f2e",
     "nonce": "0x4b6c6336198f3aff",
     "number": "0x2",
     "parentHash": "0x1bf5e60055636418c90891e234161b63c70b85644a68dcd1570ae1052a64c57c",
     "receiptsRoot": "0x056b23fbba480696b65fe5a59b8f2148a1299103c4f57df839233af2cf4ca2d2",
     "sha3Uncles": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
     "size": "0x26a",
     "stateRoot": "0x730a6f5dbff0b86dd73ff3f2ba05e0e117129514002c742c716e88ee64426019",
     "timestamp": "0x14",
     "totalDifficulty": "0x40001",
     "transactions": [
       0: {
         "blockHash": "0xadff3fcd8b8fcfb1fa9e4fd94a4fa9b10794c62d70e3db9d59e686aea8ccc4c5",
         "blockNumber": "0x2",
-        "chainId": "0x1",
         "from": "0x658bdf435d810c91414ec09147daa6db62406379",
         "gas": "0x5208",
         "gasPrice": "0x2db08786",
         "hash": "0x01d4a8006d417b25f8339501b42cfde957f85a2c18c604e69939d610933a8fde",
         "input": "0x",
         "nonce": "0x1",
-        "publicKey": "0xd9a872707aaec451b19445dd00c5ad619f36a0dcad5b035b03baf16849f719e806455742d05bf26ab4d0e715198709e0e7794c214ccde55731a9fbbd51edf2d8",
         "r": "0x5d50bd58d78c6bb56bba9f4b28b251c616231e9e35ab9733100c5245b7b469c5",
-        "raw": "0xf86501842db0878682520894658bdf435d810c91414ec09147daa6db624063798203e88026a05d50bd58d78c6bb56bba9f4b28b251c616231e9e35ab9733100c5245b7b469c5a005241e473259c43bb38387211fa93ce8d5edf98775a20f971d31192290ca3970",
         "s": "0x5241e473259c43bb38387211fa93ce8d5edf98775a20f971d31192290ca3970",
         "to": "0x658bdf435d810c91414ec09147daa6db62406379",
         "transactionIndex": "0x0",
         "v": "0x26",
         "value": "0x3e8"
+        "type": "0x0"
       }
     ],
     "transactionsRoot": "0x7ca7896b5edf21a06d64da4ed0e0a8137fc95fa3c0ad4a89d79c194d895e1a40",
     "uncles": [
     ]
   }
 }