* move fc from fluid to paddle2.0

* fix unit test

* fix some examples

* fix some examples

* Clean fliud hash

* clean fluid grid_sampler

* clean log_loss

* Move bilinear_tensor_product from fluid to static

* Fix unitests when remove log_loss

* Fix bug when move bilinear_tensor_product

* fix test_fleet_nocvm_1.py

* Add bilinear_tensor_product into all list

* Fix code style

* Fix comments in bilinear_tensor_product

* Fix comments in bilinear_tensor_product

* Fix comments

* isort all files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* revert conflicting files

* [CodeStyle][py2][U008] remove unnecessary args in `super()`

* remove remained args

* revert changes in test_pylayer_op

* Revert "revert changes in test_pylayer_op"

This reverts commit ff185a9ae738afac3b0264f61bde6c6b7f72e7c4.

* revert some changes in example code

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

* use tempfile to place temporary files

* update

* revert test_communicator

* fix test_dist_base

* test=develop, rm netifaces

* fix fleet util and gloo

* fix worker endpoints

* fix

* fix UT

* fix gloo

* fix gloo

* update gloo

* update gloo

* update gloo

* update gloo

* update gloo

* fix gloo wrapper for hdfs

* add file gloo and UT

* fix UT

* fix UT

* fix UT

* hide public method of RoleMaker

* fix UT

* GPU fleetrun support gloo

* parameterserver fleetrun support gloo

* add UT

* add UT

* fix UT

* fix get server endpoint

* fix get server endpoint

* fix UT

* hide public method of rolemaker

* hide public method of rolemaker

* hide public method of rolemaker

* Update test_fleet_rolemaker_new.py

* hide public method of rolemaker

* hide public method of rolemaker

* move paddle.fleet to paddle.distributed.fleet

* move dataset to fleet
test=develop

* fix
test=develop

* fix
test=develop

* fix
test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

Integrated Trainer of Parameter Server (API add `fluid.contrib.layers.sparse_embedding` only) (#22957)

* Integrated Trainer of Parameter Server

* add timeout and http store in communication, add revert and confirm in fleet
* test=develop

* add GeneralRoleMaker which is for general usage
* test=develop