feat_: locally handled methods package base structure

[kounkou]

Description

fixes #5417

Connector service aims at handling eth_ methods received through RPC or WS endpoints. However, some API's must be implemented locally. That's the case for :

• eth_sendTransaction
• eth_sign
• eth_chainId
• eth_requestAccounts

This PR is created to implement the base structure for implementing those API's. The PR includes implementation for the eth_chainId API.

Important changes:

• [x] Add local node base structure for eth* calls
• [x] Add eth_chainId

Test

Tested with Postman that we can query the eth_chainId

{
    "jsonrpc": "2.0",
    "id": 37,
    "result": "{\"jsonrpc\":\"2.0\",\"id\":0,\"result\":\"0x1\"}"
}