load default config from chia root directory

[JordyBaylac]

This PR has an enhancement to allow loading default port, host and certs from chia root configuration and avoid the need to specify manually.

Below is possible now:

import { FullNode } from 'chia-client';

const fullNode = new FullNode(); // options will be picked from chia config.yaml
const blockchain = await fullNode.getBlockchainState();

I have also updated some RPC calls that name were changed by the chia team (_get_block_record_byheight instead of _get_sub_block_record_by_subheight). Also _/get_unspentcoins has been deprecated and replaced by _/get_coin_records_by_puzzlehash (https://github.com/Chia-Network/chia-blockchain/wiki/RPC-Interfaces#get_coin_records_by_puzzle_hash)

[freddiecoleman]

Thanks for this.