support heter-xpu-ps

test=develop

* fix _to_tensor method of Distribution class

* Add unittest

* let dtype be consistent with value in log_prob and probs

* fix format

* fix dtype problem and change unittest

* fix dtype of Numpy class in unittest

* add formula for entropy and kl

* change formula

* fix kl formula format

* fix kl formula format 2

* change gt to np in unittest

* optimize unittest format

* delete dumplicate

* delete dumplicate 2

* extract common function used to convert dtype value

* fix conv output_size has no default value bug
* fix summary bug

update doc of paddle.to_tensor

* fix unittest format and extract common function

* change function name

* fix heter-ps multi thread

* fix doc

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* fix doc, test=develop

* update localsgd doc
test=develop

* update localsgd doc
test=develop

* fix fleet dgc amp doc, test=develop

* fix, test=develop

* fix async configs
Co-authored-by: Nliuyi05 <gavin1332@gmail.com>
Co-authored-by: NWangXi <wangxi16@baidu.com>
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

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