paddle.distributed.fleet supports dynamic graph execution.

* print detailed and clear log infos; test=develop

* support running python train.py for fleet-task; test=develop

* update set_dict method name & add aliases

* fix var name error

* fix alias formats

* use set_state_dict in unittest

* add decorator solve compatible problem

* polish decorator

* replace layer set_state_dict by patched method

* remove import monkey path layer

* fix import function error

* add unittest for coverage

* fix

* fix doc, test=document_fix

* support load infer model format state dict

* add unittests

* remove keep name table

* recolve circle inport

* fix compatible problem

* recover unittest

* polish doc and comment

* add summary for hapi

* set_default_type only take effect on python floats or complex

* fix doc

* refine paddle.stack

* support TensorArray

* add test

* fix coverage problem

* fix coverage problem

* fix sample code

* fix uniform CI random fail problem

* decrease diag_num in DiagInit

* fix dropout bug in backward when input is 1d tensor, test=develop

* add test case and refine error message, test=develop

* refine error message, test=develop

As the title

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* replace fluid.optimizer.set_dict with optimizer.set_state_dict

* replace fluid.optimizer.set_dict with optimizer.set_state_dict

* add coverage rate

* Increase coverage rate, fix code style

* Increase coverage rate, fix code style

* add fit to generate optimizer.state_dict() to save .pdopt to increase coverage rate

* delete http.log

Fix some code samples in Tranoformer apis.
test=develop

* fix sample codes, test=develop

Raise RuntimeError if run the callable object decorated by '@paddle.jit.to_static' not in dynamic mode.  (#26750)

* fix the argmin,argmax op for the paddlepaddle 2.0， add checkPoint for the argmax/argmin

* fix fluid.embedding

* add check for bernoulli and register bool for unsqueeze

* follow comments

[Dy2Stat-debugging] Fix bug: Returns True if the verbosity level set by the user is greater than or equal to the log level (#26858)

Fix an English typo in unit test.

* support mnist and resnet dygraph_to_static test

* make FLAGS_use_mkldnn a public flag

* fix test_get_set_flags

* Change name of a function

* Rerun CIs commit

* Fix oneDNN dygraph training
Co-authored-by: NAdam <38704900+grygielski@users.noreply.github.com>
Co-authored-by: Ngrygielski <adam.grygielski@gmail.com>

* add embedding 2.0

* add embedding support input int32

* update doc

* update doc

* fix optimizer sample code

* add default value for adamw weight_decay

* fix adamw

* change LearningRateDecay to _LRScheduler

* fix adamw;notest

* fix load;notest

* remove file

* bug fix

* fix code style

* bug fix

* add ut

* adamw support weight_decay=0

* fix ut

* fix set_lr doc

* fix doc

* change parameters place

* remove backend argument of init_parallel_env

* remove keep name table in transformer

* add cpu version check

* add skip unittest for init_parallel_env

* polish doc: remove func use & update example

* add FleetAPI doc
Co-authored-by: Nliuyuhui <liuyuhui@baidu.com>