Add import options for pure, pre-hash, external mu modes etc.

[jakemas]

Some consumers may only want "pure" ML-DSA, no pre-hash, external mu etc. Perhaps even, others may only want some utilities such as verify. Could we add configuration options to allow only the selected APIs? or is this something we let the consumer handle?

For the aws-lc import we could reduce unused code by omitting the HashML-DSA modes and associated files, for example.

[mkannwischer]

Yes, I'm in favour of adding configuration options for this.

We already have an option that is related: MLD_CONFIG_NO_RANDOMIZED_API So we could extend this , e.g., to

• MLD_CONFIG_NO_KEYPAIR_API
• MLD_CONFIG_NO_SIGN_API
• MLD_CONFIG_NO_VERIFY_API

and additionally

• MLD_CONFIG_NO_PURE_API
• MLD_CONFIG_NO_EXTMU_API
• MLD_CONFIG_NO_PREHASH_API

What do you think?