[FIX] RNS Resolution

[ahsan-javaiid]

Description

This PR fixes RNS resolution issue on send screen. There are two reasons due to which RNS names are not resolving.

1. Network is hardcoded in lookup field component here:

   MyCrypto/src/components/GeneralLookupField.tsx

   Line 142 in 457ec2f

   const provider = new ProviderHandler(ethNetwork);

2. In case of RSK network RPC provider does not know RNS registry address:

   MyCrypto/src/services/EthService/network/helpers.ts

   Line 28 in 457ec2f

   return new StaticJsonRpcProvider(connection, chainId);

   which in case of eth, points to correct address.

Changes

1. Remove hardcoded network in lookup field component
2. Set RNS registry address inside provider in case of RSK network

Demo

mycrypto-demo.mp4

Steps to test

1. Select RSK network
2. Enter any rns name in the address field
3. Name should resolve to address

[alepc253]

@FrederikBolding could you please take a look?