Use Int8QuantParamsBlob to pass the scale and zeropoint params (#40494)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40494
Resubmit the diff because D22124313 (https://github.com/pytorch/pytorch/commit/1ec4337b7d58fd8afbfc181f975d3940c5e2e8d6) was reverted due to CI test failures
Added the int8_gen_quant_params.cc to CMakeList.txt to fix the CI failures
Test Plan: buck test caffe2/caffe2/quantization/server:
Reviewed By: hx89
Differential Revision: D22204244
fbshipit-source-id: a2c8b668f199cc5b0c5894086f554f7c459b1ad7
