FIPS 204 - API for Module Lattice-based signatures (ML-DSA)

[athoelke]

Based on the discussion and proposal in #96 and #210, here is a definition of key types and algorithms for ML-DSA.

I have extracted the ML-DSA definitions out of the #210 PR, in which they are entangled with ML-KEM and ECIES API definitions, in order to fill out the remaining API for ML-DSA, using a similar structure to the SLH-DSA definitions in #216.

• The three parameter sets are supported
• Four algorithm variants for Hedged/Deterministic and Pure/Pre-hash options. The provision of explicit deterministic variants is an active discussion topic, see #210 and #216.
• Context values are not supported. These need an additional API to provide the context - as per existing sign-with-optional-context algorithms.

Fixes #96