newKey function
Implementation
Bip32 newKey(String mnemonic, int coinType, int index) {
final node = Bip32.fromSeed(mnemonicToSeed(mnemonic));
final accountNode =
node.deriveHardened(44).deriveHardened(coinType).deriveHardened(0);
return accountNode.derive(0).derive(index);
}