Implement eth_getProof RPC message

[facuspagnuolo]

Would be really amazing to provide support for the eth_getProof RPC message. I actually needed to migrate bunch of tests to geth to make them work :)

Please let me know if I can help with it.

[davidmurdoch]

Thanks for the feature request, @facuspagnuolo! I'd like to start implementing more of the DRAFT status EIPs into ganache-core sooner than we have been. So if you'd like to put in the effort to make this happen I'd happily review and merge (likely behind a new option/flag we've been wanting to implement: enable-eips: Array<string> (we're still working on the name).

The bulk of the code will need to go in https://github.com/trufflesuite/ganache-core/blob/develop/lib/blockchain_double.js

Let me know if you need any help with the code base!

[simon-jentzsch]

This would be great, even though I don't have much time right now, I would love to help ( I did the implementation for geth and parity ). So if I can help, just ask!

[saurik]

Related: #725