Secure the Poseidon hash function with test vectors

[zac-williamson]

PR #3118 implements the Poseidon2 hash function, but currently lacks 3rd party test vectors to cross-reference the correctness of the hash function.

Existing poseidon2 implementations are parametrised by the following parameters:

• sponge rate+capacity (t from the paper)
• prime field type
• round constants
• matrix diagonal constants

I have not been able to find another implementation that uses the same prime field and t parameter. Additionally, we need to use test vectors where the round/matrix constants aren't hardcoded magic numbers (i.e. derivation method is documented so we can reproduce).