feat: NIVC circuits + tests

[Autoparallel]

Completed Work

This PR addresses:

• Closes feat: NIVC circuits #97

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OLD TODOs

Current Goals and TODOs

Most of the work is done, only a few bugs, tests, and upgrades remain.

Get the NIVC circuits in this repo, properly tested, and fully functional (in as far as the parsers themselves are).

Notes

Most of the (currently) 13K lines change is storing JSON. We can remove this JSON storage later and chain these together using circuit.compute(input, ["step_out"]) and taking the output from there and using it for the subsequent input.

I made JSON files now because I wanted temporary storage for introspection on the values.

[Autoparallel]

@lonerapier this is ready for review.

I think the last steps are:

• decide how we want to do the final value extraction. Right now I wrote a new output signal value. I think we may want to have the step_out all zeroed out and perhaps even set the curr_depth signal (step_out[-1]) to be something like -1 (bn254::max). This means no circuit can ever meaningfully placed after this one. This gives us assurance no funny business happens after parsing and we can even assert that a ROM must end with this circuit.
• to do a final clean up to make these circuits as simple as possible, easy to read, and minimal diffs on this change.
• get rid of the json files and set this up to do the NIVC in order and in memory. Having the files was just for debugging. May be worth leaving comments on how to have this generate files though in case we ever need to debug this again.

[lonerapier]

onto NIVC we go!!