* dygraph post training quantization

* refine the ptq config

* refine ptq quantizer

* Combine amp and qat
* add unit test

* del py2 code2

* fix test timeout

* Add wrap for functional api
* Refine the wraped api
* Add unit test for quant functional layers
* Update all unit tests for dygraph qat

* Update paths to Quant models

* Update description

* support ernie trt-int8 for inference

* fix reshape

* Support converting the model from fp32 to fp16

* Use layer to calculate output scale
* add backward for moving_average_abs_max_scale and save output scales to op's attr

* Refine saving output scale to infer program

* Fix skip_quant in QAT

* Refine calculating output scale of dygraph qat, test=develop

* Support loading parameters from checkpoint to save quantized model

* Fix the unittest test_moving_average_abs_max_scale_op

* Add unittest of save_quantized_model from checkpoint

* Add comments to explain the function

post quantize support insert fake_quantize_dequantize node before the OPs that will be used in VIS's faceid models (#30659)

test=develop

* Fix the error of save_quantized_model

* Collect weight threshold of lstm, test=develop

* skip quantizing ops in cpu inference, test=develop

* Implemented AddQuantDequantPass in imperative quantization.

* Supported LeakyReLU Quantization

* For meeting coverage rate.

* Changed the file name of test of AddQuantDequant

* Implemented more Quantized NoWeightLayers.

* Fix the loss cannot align problem between static and dynamic model quantization, add swish as supported quantized layer in imperative quantization.

* remove noweight_list

* support 2.0 API such as Pool2D and ReLu

* Quantization supports 2.0 APIs

* Fix the error of save_quantized_model

* Avoid the scale to be infinity in quant2_int8_mkldnn_pass, test=develop
* support quantized model for paddle2.0 dygraph, test=develop

* Support quantizing program_desc, test=develop

* Fix unittest:test_imperative_skip_out

* rm check_import_scipy, rm chunk_eval and mean_iou in paddle.metric.__init__.py

* Revert "rm check_import_scipy, rm chunk_eval and mean_iou in paddle.metric.__init__.py"

This reverts commit 179ba8c2b22bc31fe8d8a126e31820792cbd0f4e.

* delete paddle.metric.chunk_eval and paddle.metric.mean_iou

* delete paddle.nn.clip and paddle.nn.clip_by_norm

* delete paddle.nn.functional.activation.hard_sigmoid and paddle.nn.functional.activation.hard_swish

* delete paddle.nn.Pool2D, paddle.nn.BilinearTensorProduct, paddle.nn.RowConv, paddle.nn.functional.row_conv

* fix extension import error

* fix unittest for row_conv and Pool2D

* Optimiz the unittest test_imperative_out_scale

test=develop