Support EMVB

[mtbarta]

https://arxiv.org/pdf/2404.02805.pdf

This is an optimized retrieval process over PLAID.

This might be more of a story/epic, in that we probably have multiple steps before this task is complete.

• [x] Enable retrieval with either PLAID or EMVB
• [ ] Build LintDB for avx512 instructions
• [x] Consolidate engine configuration within the index

[mtbarta]

We incorporated methods for EMVB without intrinsics, so this isn't fully done.

However, I'd like to pause this workstream as more research happens. In the mean time, we can add intrinsics in a more generalizable fashion.