Consider renaming ML-DSA constants

[djc]

Problem:

Cosmetic/stylistic suggestion: consider renaming the ML-DSA constants to use an ML_DSA_ prefix rather than MLDSA_. This seems more idiomatic with how Rust style is normally used.

Solution:

Add an extra underscore for all 6 constants.

Requirements / Acceptance Criteria:

The relevant standard is in the API naming guidelines, but it isn't that explicit on this particular point:

https://rust-lang.github.io/api-guidelines/naming.html#casing-conforms-to-rfc-430-c-case

My argument is that "ML" and "DSA", usually hyphen-separated in prose, should be construed as 2 words in the context of naming them.

Further context

The rustls-post-quantum crate will soon offer ML-DSA support as an option.

rustls-pki-types now exposes alg_id::{ML_DSA_44, ML_DSA_65, ML_DSA_87}.

rustls-webpki now exposes aws_lc_rs::{ML_DSA_44, ML_DSA_65, ML_DSA_87}.

[justsmth]

Hello! -- It looks like we were following the "no-separator style" used by the analogous constants in AWS-LC. But I agree that the separator should be there, and I see that OpenSSL is also using the separator in their APIs related to ML-DSA.

I'll check with the team to get a consensus, and hopefully put up a PR for this soon. Thanks for the feedback!

[justsmth]

The PR for this has been merged. The new/renamed constants have been added and the current constants are marked deprecated to make transition easier. This change should be available in our next release.