feat: node api proxy

[r4mmer]

Acceptance criteria

• Implements the api described on the design [Design] Proxy full-node api #83
• Does not alter parameters passed to the full-node and returns the exact response from the full-node

[luislhl]

It seems like we are using this same response for a lot of cases, even the ones that are not timeout.

And the variable name does not represent its content Timeout due to too many transaction

Is that right?

[r4mmer]

Yes, the previous response was "This address is blacklisted" but the reason of the blacklist is a timeout due to too many transactions. This message was changed because it is showed to the user on the frontend so it should reflect the actual reason.

[luislhl]

but the reason of the blacklist is a timeout due to too many transactions

I'm not sure I understand this sentence.

I brought an example from line 18 in this file to make my point clearer:

        if self.node_api_gateway.is_blacklisted_address(address):
            return ADDRESS_BLACKLIST_RESPONSE

I don't understand why in this case we return Timeout due to too many transaction to the user.

[andreabadesso]

Other than @luislhl comments, this looks good to me