Add "debug_storageRangeAt" JSON-RPC method support

[aftermathdigital]

Using Remix's local web3 provider to debug transactions submitted to a local hardhat node fails with the following error:

debug_storageRangeAt - Method not supported

Searching for debug_storageRangeAt in the hardhat repo returns no results, so I guess this method is just not implemented at present.

Reproduction steps:
I used a forking provider similar to the following, but I don't think you need to:

module.exports = {
  solidity: "0.4.24",
  networks: {
    hardhat: {
      chainId: 31337,
      forking: {
        url: "https://mainnet.infura.io/v3/api_key"
      }
    }
  }
};

1. spawn a node with npx hardhat node
2. configure solidity to use the local web3 provider
3. deploy a contract
4. perform a tx interacting with the contract
5. Attempt to debug the transaction
6. Step forward once

At this point the remix debug pane dissapears (presumably due to an unhandled error on their side) and the hh node console is spammed with debug_storageRangeAt - Method not supported

[fvictorio]

Thanks for opening this @aftermathdigital. This will require some investigation. Especially: how does that method behave? Is it documented somewhere? Will this be enough for remix's debugger to work with Hardhat?

[aftermathdigital]

Regarding documenting the method... the best I can find is this: ethereum/go-ethereum#14350 which is the pull request that implements it in Geth.

I don't know if this will be enough to make remix work - but ganache has a similar issue open where they seem to think it is all they need (since you already have debug_traceTransaction) : trufflesuite/ganache#248

GetBlock have a little bit of documentation here, too: https://getblock.io/docs/available-nodes-methods/ETH/JSON-RPC/debug_storageRangeAt

It sounds like a bulk-version of eth_getStorageAt, so its implementation may be quite similar.

[tcoulter]

Note to anyone reading the above comment: The Ganache issue for debug_storageRangeAt referenced above has moved to here: trufflesuite/ganache#1037