FP [6,8,12] quantizer op (#5336)
Flexible-bit quantizer-dequantizer library with fp6/fp12/fp8 support
Requires Ampere+ architecture, this is due to the initial focus of this
op only on `bfloat16` input types.
Co-authored-by: Reza Yazdani <reza.yazdani@snowflake.com>
