Better build detection for Artifacts for more diverse instruction sets

[AndyGrant]

Currently, private instances pick between linux/windows, avx2/avx512 (VNNI), and pext/popcnt. And then we enforce that all combinations of avx2/avx512 and pext/popcnt exist. Instead, let the engine config specify as few or as many as they like.

The client will then look through them to determine what they desire. The new standards will be: ssse3, avx, avx2, avx512, vnni. As well as pext popcnt.

We will also add an explicit check for 7B12 processors, which are Zen2 but have proper PEXT support.