Add ARI support

[hslatman]

Discussed in #2160

^{Originally posted by juju4 February 9, 2025}
https://datatracker.ietf.org/doc/html/draft-ietf-acme-ari-07#name-getting-renewal-information
https://community.letsencrypt.org/t/ari-implementations/218730/15

I tested with ansible module community.crypto.acme_ari_info and it returned
"The ACME endpoint does not support ACME Renewal Information retrieval"

[dopey]

We discussed this feature request internally and have decided not to prioritize at this time.

Step CA aims to robustly implement the basic functionality of the ACME spec, as it relates to a private PKI. We do not believe this feature falls within this scope.

That said, we are open to having our minds changed by members of the community.

[hslatman]

@dopey after reading the RFC, I think https://datatracker.ietf.org/doc/html/draft-ietf-acme-ari-07#section-5 might be interesting to support, as it allows to get a lineage of certificates issued through ACME renewals. It's described independent of ARI, and I think it can work without it, but I don't know if that's what will happen in practice with ACME clients adopting ARI.

A very naive implementation of ARI could suggest renewal times that are within the certificates last third or half of validity. Something that's more stateful will require more configuration.