* enable async copy and  add wait before sync operation

* remove unneccessary wait

* add FillNpuTensorWithConstant

* refine

* fix fill_constant

* change TensorFromVector to FillNpuTensorWithConstant

* fix ignored api

* delete extra unittest

* fix little error

* fix update_loss_scaling_op_npu and check_finite_and_unscale_op_npu

* change TensorCopySync to TensorCopy

* delete useless Wait and add StreamWait

* fix npu_stream error

* fix check_finite_and_unscale_op_npu TensorCopy

* only save stream wait

* fix NPUDeviceContext in all c++ unittest

* delete wait
Co-authored-by: Nzhiqiu <chenqiuliang@baidu.com>

* fix reading flags from env

* fix problem caused by async run

* support partial grad

* support elementwise_add_grad npu kernel

* add unittest

* fix bug?

* add npu sub op

* fix typo

* rename test

* fix bug

* fix bug

* add fp16 kernel

* fix typo

* support sub grad op

* support elementwise_sub_grad op
Co-authored-by: Nfrankwhzhang <frankwhzhang@126.com>