XEP-0474: SASL SCRAM Downgrade Protection support

[Neustradamus]

Can you add XEP-0474: SASL SCRAM Downgrade Protection support?

• https://xmpp.org/extensions/xep-0474.html

Linked to:

• RFC 9266: Channel Bindings for TLS 1.3 support #539
• XEP-0388: Extensible SASL Profile support #545
• XEP-0440: SASL Channel-Binding Type Capability support #546
• XEP-0474: SASL SCRAM Downgrade Protection support #551
• https://github.com/maranda/metronome/issues/554
• https://notes.valdikss.org.ru/jabber.ru-mitm/
• https://snikket.org/blog/on-the-jabber-ru-mitm/
• https://www.devever.net/~hl/xmpp-incident
• https://blog.jmp.chat/b/certwatch