This is Starkom's implementation of the Poseidon2 algebraic hash.
The implementation is generic and works on any prime field, but we always allocate exactly 1 state
element for capacity, resulting in 128-bit security.
We also provide configurations for the BLS12-381 and BlueSky prime fields, for T=3 and T=4.
NOTE: the BLS12-381 configurations are controlled by the `bls12_381` feature flag, which is disabled
by default.