todo: merge AVX-512 version of PQFastScan

[alexanderguzhva]

Faiss PR https://github.com/facebookresearch/faiss/pull/3276

AVX-512 implementation for PQFastScan for QBS.
For local benchmarks on 4th gen Xeon, the QPS is up to 10% higher, mostly for a single query case. But as far as I remember, production cases would show higher performance improvements.

It cannot be cherry-picked or copy-pasted, because Faiss baseline uses #ifdef mechanism for deciding whether to use AVX-512, and Knowhere uses dynamic hooks. Some additional code is needed.