feat: onFinished event for the last result recognition

I don't see a way to detect the last recognition, once you start getting results there is no way to detect the last inference,

`SpeechRecognition.addListener('partialResults', async (data: any) => {
})`

I would like either an event for finished Results or the same partialResults event can emit a property when is the last results

I'm trying the tricky solution that is to set a timer, when you don't receive partial Results after some time, you know it has finished

Start at the SpeechRecognition.addListener('partialResults') entry point described in the issue and inspect how recognition results are exposed. Define completion behavior for the final recognition and verify that the chosen event or result property reliably signals when recognition has finished.

Written by the indexing model from the issue text.