Have both rest and rpc endpoints in cfg

[udit-gulati]

The js client for a given network can either use the REST or RPC url based on the implementation.

Having them as rest_endpoint and rpc_endpoint in place of endpoint will make it easier to understand for the user and if the js client only requires RPC endpoint then rpc_endpoint value can be skipped in the config and vice-versa.

While doing node-info, user can confirm if REST or RPC endpoint was required.