* Doc update with Ernie QAT INT8 benchmarking

test=develop

* fixes after review

test=develop

* remove ernie part, test=develop test=document_fix

* Fix model name for qatv2

test=develop test=document_fix

* Add Ernie data

test=develop test=document_fix

* update ERNIE benchmark with baidu QA results, test=develop test=document_fix
Co-authored-by: Nbingyanghuang <33643817+bingyanghuang@users.noreply.github.com>
Co-authored-by: NMichał Gallus <sand3r@interia.eu>

* a test for Ernie QAT INT8 accuracy check

test=develop

* Remove NLP comparison test to split PRs

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* Fix typo and tabs, delete commented lines

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* re-combine the 2 PRs, test=develop
Co-authored-by: NMichał Gallus <sand3r@interia.eu>
Co-authored-by: Nbingyanghuang <33643817+bingyanghuang@users.noreply.github.com>

* post_training_quantization support set bits, test=develop

* up, test=develop

* support weight quantization in post_training_quanzitaion, test=develop
* add test for weight quantization, test=develop

* add mul and matmul quantization, test=develop
* add test for matmul, test=develop

* use snake_cased Layer name

* add named_parameters and named_sublayers api

* add include_sublayers param, add unittest
test=develop

* fix named unittests
test=develop

* fix unittest
test=develop

* add api docs
test=develop

* arg fix
test=develop

* reserve rnn_impl name_scope for static graph
test=develop

* fix load static param
test=develop

* fix load static param
test=develop

* add special way to add distribute vars， Update Pyramid hash op

* add shuffle batch op, test=develop, test=document_preview

* fix size_t conflict and check_output test=develop, test=document_preview

* fix bug test=develop, test=document_preview

* add unittest of shuffle_batch layer test=develop, test=document_preview

* fix py coverage and op input type, test=develop, test=document_preview

* fix py coverage, test=develop

* fix en doc, test=develop

* move to contrib test=develop

* add unique_name test=develop

* invoke shuffle_batch in contrib.layers test=develop

test=develop

* fix post training quantization bug of memory constrained, support the input be different, test=develop

* remove build_once & name_scope (Conv2D)
test=develop

* fix unittest
test=develop

* Conv2DTranspose

* Conv3D & Conv3DTranspose
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* Pool2D & BatchNorm

* Embedding

* LayerNorm

* GRUUnit & NCE

* PRelu

* BilinearTensorProduct

* GroupNorm & SpectralNorm

* TreeConv
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* fix LayerNorm in transformer unnittest
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* disable LayerNorm or BatchNorm in multicard
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* refine Layer.create_parameter api
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* refine LayerNorm, remove begin_norm_axis param, add normed shape check
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* LayerNorm bug fix
test=develop

* fix ci bug for deleting data files, test=develop

* update, test=develop

* update benchmark for int8v2, QAT1, QAT2 accuracy and performance
test=document_fix

* change according to reviews
test=develop test=document_fix

* improve some descriptions and some models
test=develop test=document_fix

* update models benchmark data
test=develop test=document_fix

* update int8v2 and qat2 performance
test=develop test=document_fix

* add ut for comparing FP32 and QAT INT8

* add save qat transformed model python script
test=develop

* updated

* added missing file

* add "with_label"
test=develop

* performance benchmark as unit test
test=develop

* change names of unnecessary thing

* Change CMakeList.txt for model downloading and UT
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* change names of functions and params for more readable code
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* Change PADDLE_ENFORCE messages
test=develop

* fix indent problems
test=develop

* indent problems
test=develop

* fix some typos in AMP. test=develop

* delete useless codes. test=develop

* add global value getter setter, test=develop

* fix error messages, test=develop

* support set model_filename and params_filename in post_training_quantization, test=develop

* Support  more ops in post training quantization, and save the output scale in quantized op.
* Update docs in post training quantization and qat 

test=develop

* Fix bug for inserting add_quant_dequant_op to same variable repetitively in add_quant_dequant_pass, test=develop

* add post training quantization, test=develop
* specify the quantizable op type, test=develop

* add custom black varname test=develop

* fix dtype test=develop

* fix num test=develop

* fix ut test=develop

* fix coverage test=develop

* fix blackvar names test=develop

test=develop