Generate generators in comptime

[nventuro]

As mentioned here, aztec-nr/src/generators.nr has a bunch of hard-coded generators. These should be generated at comptime instead.

[jp4g]

This is causing some issues for people who want to use notes - if you want a note with > 4 (using #[note]) or 5 (using #[note_custom_interface]) you need to use std::hash::derive_generators at runtime or manually log out the generators then set them as constants yourself (i didn't see a js api for this but tbh didn't look too hard).

A: requires the dev to hunt down where the #[note] isn't working
B: requires the dev to do all the boilerplate for custom note interface that is really just being done for the sole point of changing fn compute_note_hash(self)

By no means breaking with the but it introduces a ton of friction in an otherwise reasonably easy process

[nventuro]

@jp4g yes, we also need to extend this so that it's not so few of them. Thanks for the heads up!