Fix poseidon sponge bug

[kilic]

Description

Poseidion sponge skips a permutation in a certain condition:

• Sponge is in squeeze mode
• Number of elements in the call equals to the rate

So that it returns same elements in subsequent calls which is demonstrated in the first commit of this PR. Problem is fixed in the next commit. I also added a simpler independent implementation to apply cross fuzz test and must be removed when this PR matures. I've checked and asked around if any production project uses PoseidonSponge at the moment but don't see any and I think this PR is safe to be opened.

I also come across another strange behaviour which I feel that it is not intended. In a such condition:

• Sponge is in squeeze mode
• Number of elements int the call equals to zero
• Internal index is factor of rate but not zero

It applies a useless permutation rather than jsut returning an empty output vector. I've also filed this it in the comments of cross implementation.

Another thing I would like to add as discussion is that squeezing 0 elements in absorb mode changes the mode to squeeze. So for example output of absorb(3), absorb(4), squeeze(1) is not the same as absorb(6), squeeze(0), absorb(1), squeeze(1) This would be intended but I find allowing to squueze 0 elements confusing as an api user.

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• Targeted PR against correct branch (main)
• Linked to Github issue with discussion and accepted design OR have an explanation in the PR that describes this work.
• Wrote unit tests
• Updated relevant documentation in the code
• Added a relevant changelog entry to the Pending section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

[Pratyush]

Thank you for the fix!