crypto: add the ChaCha20Poly1305 AEAD as specified in RFC8439

Summary:
This adds an implementation of the ChaCha20Poly1305 AEAD exactly matching
the version specified in RFC8439 section 2.8, including tests and official
test vectors.

This is a partial backport of core#28008 and a backport of core#29815
https://github.com/bitcoin/bitcoin/pull/28008/commits/9ff0768bdcca06836ccc673eacfa648e801930cb

Squashing with ccore#29815 bypasses a change from core#29404 (#include <config/bitcoin-config.h>)

Depends on D19017

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D19018