FR: getVoices options bag

It would be good to have an option to fetch voice(s) from `getVoice` API:

Instead of: 

```js
window.speechSynthesis.getVoices().filter(v => v.lang == 'en-US');
```

It would be useful to have an options bag:

```js
window.speechSynthesis.getVoices({locale:'en-US', gender:'female'});
```