Smoothl1loss (#5256)

* implement smoothl1loss

* add smoothl1loss  test

* fix bug

* fix bug

* remove swp file

* fix bug

* refine

* refine_grpc_cmake_for_conda

* refine

* refine

* refine

* rm

* refine

* refine

* refine

* refine

* also fix opencv

* refine

* reorder

* refine gflags and glog

* rm useless

* rm useless

* rm useless

* refine

* rm var only available in protobuf

* add not-suppported check for reduce and size_average

* add test for datatype of int32

* auto format by CI

* implement backward and rebuild Factor

* rebuild Factor for smooth_l1_loss_grad

* auto format by CI

* fix bug

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