* remove fluid.data

* fix typro

* fix somme unitest error

* fix conflicts

* fix sample code error

* fxi sample coder error

* fxi sample code error

* fxi sample code error

* fix xpu test error

* fix xpu test error

* Delete ps_pb2.py

* fix test error

* fix typro

* fix sample code error

* fix comments

* fix test norm op data

* fix sample code error

* fix conflicts

* remove paddle.fluid.layers.layer_norm

* templatedoc import from paddle.fluid.layers.layer_function_generator

* del import of fluid.layers.layer_norm in __init__.py

* add import of ..common.layer_norm in __init__.py

* fix bug in UT

* fix doc

* clean elem_arithmetic part2 unittest

* fix test_model_cast_to_bf16

* restore test_model_cast_to_bf16

* add isort config

* isort all files

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle][F401] remove unused imports in unittests/dygraph_to_static

* [CodeStyle][F401] remove unused imports in unittests/ir

* add noqa after required 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

* skip_layernorm_op done

* add unittest

* slice op convertor support trt < 6

* skip_layernorm only work in ernie

* add skip_layernorm pass. test=develop

* Implement a common python unittest to test the ir passes.
test=develop

* Save the results in np.array and support to startup on CPU.
test=develop

* Fix the unittest.
test=develop

* Add check_program to check whether the optimized program is different from the origin one.
test=develop

* Remove the inferface all_ops.
test=develop

* Add exception test in pass_test.
test=develop