* copy api from paddle to paddle.fluid, test=develop

* fix optest, test=develop

* API/OP (affine_channel, group_norm, layer_norm, random_crop, unpool, log_loss) error message enhancement test=develop

* Error message enhancement of 6 op, test=release/2.0
* refine huber loss unittests, test=release/2.0

* cherry-pick OP Normal, Uniform, Xavier Initializer, smooth_l1, mean_iou error message enhancement (#23751)  test=release/2.0

* enhance pad.* error message, test=develop

optimize compare and logical ops error info, add test case for this ops， add some test case for those ops

* OP error message enhancement of l2_normalize, matmul, mean, etc 

* OP clip, merge_lod_tensor, convert/elementwise error message enhancement. test=develop

Fix the support the float16 of scale op, add delete the raise case for fp16

* add approximation for gelu, test=develop

* add functional conv

* add test and doc for function convs, test=develop

* update ConvTransposeOp's InferShape and error message, test=develop

* add hsigmoid, row_conv in paddle.nn(functional and layer), test=develop

* fix hyperlinks in docstring

* error message enhance for clip_by_norm. test=develop

* fix clip_by_norm. test=develop

* fix clip error message. test=develop

1. update error info of the ops (abs, acos, asin, atan, ceil, cos, exp, floor, log, pow, reciprocal, round, rsqrt, sin, sqrt, square, tanh)
2. add the unittests of the above refered ops (test error info)

API(has_inf, has_nan, cumsum, fsp_matrix, increment) error message enhancement, test=develop (#23769)

* API(argsort, argmax, argmin, cast, diag) add error message，and the same time add the test cases for those apis.

Those ops include，scale， sum， sums，unique_with_counts，unique，
wherre， add error message and test case

* error enhance,test=develop

* update,test=develop

* update type, test=develop

* replace inout_check, test=develop

Ops(relu6/selu/soft_relu/softshrink/stanh/swish/thresholded_relu/hard_shrink/hard_sigmoid/hard_swish/hsigmoid/maxout) error message enhancement (#23718)

OP(retinanet_detection_output, retinanet_target_assign, sigmoid_focal_loss, deformable_roi_pooling) error message enhancement. test=develop (#23726)

* test=develop modify some op for dyg rcnn

* refine example code in en doc, test=develop, test=document_fix

* update shape to make it meaningful, test=develop, test=document_fix

error message enhancement for py_func op. 

* solve the conflict of ops with the same name. test=develop

* rename op paddle.fluid.matmul to paddle.matmul
* modify original API fluid.layers.matmul,and add new API paddle.matmul

* Add the matmul, elementwise_euqal, elementwise_sum ops to API2.0
* Fix the import meesage in common_ops_import
* Update the test cast for mm

This reverts commit abe3e690.
test=develop

* solve the conflict of ops with the same name. test=develop

* add functional conv

* add test and doc for function convs, test=develop

* update ConvTransposeOp's InferShape and error message, test=develop

* add inplace_abn_op. test=develop

* add fleet pslib pull and push sparse op and push dense op
* test=develop

* expand parameters, test=develop

* support resnet, test=develop

* fix resnet, test=develop

* support duplicable out, test=develop

* support ptb

* fix bugs, test=develop

* support null input, test=develop

* fix bugs, test=develop

* fix batchNorm is_test, test=develop

* refine code, test=develop

* follow comments, test=develop

* follow comments, test=develop

* follow comments, test=develop

* follow comments, test=develop