Add support for punctuals audio reactivity (lo, mid, hi)

[cleary]

Punctual takes audio input and can use it to create reactive visuals with lo, mid, hi values eg

lo >> add;
circle 0 mid >> add;
hline 0 hi >> add;

It's not currently working in flok

[jqueraltmo]

Note that these functions are intended to react to the "internal" audio, that is, the audio generated inside the ensemble, as opposed to ilo, imid and ihi that takes the "external" audio (from a mic, for example), and which are working fine.

The Punctual object has a setAudioInput that receives a WebAudioNode which I suppose is the Punctual (typescript) name for an AudioNode from the JS Web Audio API.