Add fake quantize op (#5690)

* init fakequantization op

* add backward op for fake_quantization

* add min_max_observer op and refine fake_quantization

* fix min_max_observer bug

* add moving_average_min_max_observer op

* add test example for min_max_observer

* add min_max_observer test

* add moving_average_min_max_observer op test

* fake quantization has bug

* try to fix zero_point calc bug

* fix test bug

* fix quantize op bug

* add docs for min_max_observer_op

* add docs for moving_average_min_max_observer_op

* refine doctest

* build docs for quantization

* refine doctest

* fix moving_average_min_max_observer op

* fix comments

* add post quantization op

* fix quantization op bug

* add doctest

* fix comments

* fix comments

* auto format by CI

* fix bug

* fix bn ci bug

* fix doc bug

Co-authored-by: oneflow-ci-bot <ci-bot@oneflow.org>
Co-authored-by: oneflow-ci-bot <69100618+oneflow-ci-bot@users.noreply.github.com>