Poseidon parameter generation

[redshiftzero]

This is a start towards implementing Poseidon parameter generation in Rust The idea is for this to be an independent implementation of the parameter selection logic described in the original Poseidon paper (I'm annotating where each equation is coming from in comments).

TODO:

• [x] implement algs 1-3 from https://github.com/penumbra-zone/poseidon377/blob/main/vendor/hadeshash/code/generate_parameters_grain.sage#L167 - not needed anymore! see fa04278081ca62418fd66bee4c592a89ad43e279
• [x] generate choice of alpha from modulus - doing in #7
• [x] enable conversion to ark-sponge Parameter struct - #9
• [x] round constants #8
• [x] other optimizations? (e.g. appendix B method)

[redshiftzero]

This has an implementation of the round number and MDS matrix generation, I've filed followups for the remaining tasks (#7 #8 #9) & will do the remaining work in smaller followup PRs