[FR] Sentence Trigger

[contagon]

For all the new voice assistant stuff being developed currently, it'd be awesome if sentence triggers made their way to pyscript. Something like this would be awesome,

@sentence_trigger("activate dance mode")
def dance_mode():
    dance_lights.turn_on()
    return "dance like no one is watching!"

where the return value is the "conversation response" and spoken by the triggered voice assistant.

I had planned to give this a try once I did the easier webhook triggers (in #592), but handling the return response ended up not as straightforward as I had expected and I frankly haven't found the time. Happy to collaborate if someone wants to tackle this or do it together. I think we could track any progress that happens here if @craigbarratt is open to a PR :)

Note, this is also similar to the request in discussion #591.

[ALERTua]

@craigbarratt this one is for you :)