CVE-2026-80212: fix unbounded memory growth in the DNS resolver by no longer
permanently registering an on-demand class for each unknown (type, class)
pair as a Generic constant and a ClassHash entry, and by comparing generic
resources and questions by their type and class values rather than by class
identity
CVE-2026-80213: enforce the RFC 1035 DNS label and name size limits when
encoding by making the 63-octet label limit an invariant of Label::Str,
guarding put_string and put_label, counting the encoded form in get_labels,
and raising ResolvError for an oversized name in Name.create