Aligning algo names to NIST drafts

[falko-strenzke]

@TJ-91

I propose to rename the algo names as MLKEM, MLDSA, SLHDSA. I think an underscore in the name would only cause ambiguity when reading function names, etc.

[TJ-91]

For function names I'd write it in lower case as that seems to be the default in libgcrypt. Inside strings (e.g. returning the algorithm name), I'd prefer ML-KEM etc.

[falko-strenzke]

For function names I'd write it in lower case as that seems to be the default in libgcrypt. Inside strings (e.g. returning the algorithm name), I'd prefer ML-KEM etc.

Agreed.