* split modular inversion in its own file
* Stash fast GCD inversion https://eprint.iacr.org/2020/972.pdf
* Stash Pornin's bingcd -> issue with inner modular reduction
* Implement Bernstein-Yang inversion
* Avoid Nim checks on signed integers (32-bit runtime issue)
* cleanup: remove old inversion impls
* cleanup: static moduli, move div2
* small comments (skip ci)
* comment cleanup (skip ci)
* fix total iterations on 32-bit
* Add batch conversion to affine coordinates using simultaneous inversion trick
* fix conditional setZero and batchAffine conversion
* cleanup unneeded branches following affine conversion unification
* Fix batchAffine with zero inputs and add fuzz failure to test suite
