* mv ps distributed dir

* fix

* add del auto_parallel

* add auto_parallel

* fix ps

* fix bug

* fix test bug

* fix test bug

* merge develop fix error

* merge develop fix error

* merge develop fix error

* replace paddle.fluid.layers.data and remove io.data

* partial commit

* partial commit

* partial commit

* partial commit

* partial commit

* partial commit

* remove data in fluid.layers.io.__all__

* fix errors

* fix unitests

* fix unitest

* fix unitests

* fix unitest

* fix unitest

* fix unitests

* fix unitest

* fix test_layers unitests

* fix typro

* fix unitest

* fix unitest

* fix unitest

* fix typro

* fix unitest test_model_cast_to_bf16

* fix test_reducescatter

* fix collective unitest

* fix collective unitests

* fix collective unitests

* add coverage

* fix add layers.data

* re run ci

* fix some typro

* fix samplecode error

* fix samplecode error

* add isort config

* isort all files

* add test for rsample

* add assert in test_backpropagation

* fix bug

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* add LogNormal API

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* fix bug

* add comment

* fix bug

* fix docs

* fix bug

* fix bug

* fix bug

* add test

* add test

* change the args type of Normal sample

* fix bug

* fix bug

* fix bug

* fix bug

* add test

* add test

* format

* add comment

* add comment

* add comment

* add comment

* format code

* fix bug

* fix bug

* fix bug

* add comment

* remove name parameter for LogNormal

* organize imports

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

* add random varaiable transformations API for paddle's distribution package

* add TransformedDistribution API for paddle's probability distribution package

* add random variable transformation unitests for static graph

* replace math.prod which not support python3.7 with functools.reduce

* add Independent and TransformedDistribution distribution

* add unittests for constraint

* fix typo and AffineTransform sample code error

* add mean,variance,rsample abstract method for Distribution

move distribution.py into distribution package and split into different file for better scalability (#38047)