message: feat(utxo-lib): add methods fromOutput, fromOutputWithPrevTx
  Helpers to create `Unspent` values from `tx` and `vout`.
  Issue:
diff: import { TxOutput } from 'bitcoinjs-lib';
  import { Network } from '..';
  -import { toOutputScript } from '../address';
  +import { fromOutputScript, toOutputScript } from '../address';
  import { UtxoTransactionBuilder } from './UtxoTransactionBuilder';
  +import { UtxoTransaction } from './UtxoTransaction';
  /**
  * Public unspent data in BitGo-specific representation.
  @@ -43,6 +44,34 @@ export function toOutput<TNumber extends number | bigint>(u: Unspent<TNumber>, n
  };
  }
  +/**
  + * @return Unspent from TxOutput
  + */
  +export function fromOutput<TNumber extends number | bigint>(
  + tx: UtxoTransaction<TNumber>,
  + vout: number
  +): Unspent<TNumber> {
  + const o = tx.outs[vout];
  + if (!o) {
  + throw new Error(`invalid vout`);
  + }
  + return {
  + id: formatOutputId({ txid: tx.getId(), vout }),
  + address: fromOutputScript(o.script, tx.network),
  + value: o.value,
  + };
  +}
  +
  +export function fromOutputWithPrevTx<TNumber extends number | bigint>(
  + tx: UtxoTransaction<TNumber>,
  + vout: number
  +): UnspentWithPrevTx<TNumber> {
  + return {
  + ...fromOutput(tx, vout),
  + prevTx: tx.toBuffer(),
  + };
  +}
  +
  /**
  * @param outputId
  * @return TxOutPoint
  