* Add cache for Transformer encoder.

* Bug fixed.

* add unittests for transformer encoder.

* rename manual_seed to seed

* rename xxx1d-->xxx1D, xxx2d-->xxx2D, xxx3d-->xxx3D

* rename manual_seed --> seed

* do not rename .cc, .cu and .h file

* rename manual_seed --> seed

* rename manual_seed --> seed

* rename manual_seed --> seed

* rename manual_seed --> seed

* disable_static on doc example code

* donot change manual_seed on generator

* add enable_static on sample code

* convert python/paddle/fluid/layers/nn.py to bak

* fix typo

* fix code style

* fix seed to manual_seed when call functions of Generator()

* fix bug

* add transformer generate square subsequent mask api

* add dtype for input, update doc, use -np.inf

* add dtype for input, update doc, use -np.inf

* Makes the Bind Method more intelligent

* Makes the Bind Method more intelligent

* fix unittest

* fix unittest

* fix conflict

* refine manual seed

* fix ci problem

* fix unittests

* fix unittest

* set is_init_py=false in manual_seed

* fix unittest

* fix bernoulli_op

* fix(unittest): change random_seed to manual_seed

* 🐞fix(unittest): fix manual_seed

* trigger ci

* fix test_sentiment

* fix test_imperative_save_load

* fix test_uniform_random_op

* fix test_uniform_random_op

* fix test_jit_save_load

* merge develop

* fix manual_seed

* fix manual_seed

* use global engine

* use shared_ptr

* fix double free

* fix bug

* fix bug

* fix bug

* fix test bug

* fix test bug

* fix test bug

* fix ci

* Add MultiHeadAttention api.
test=develop

* Add MultiHeadAttention cache type and gen_cache.
test=develop

* Add TransformerEncoderLayer and TransformerEncoder.
test=develop

* Add Transformer decoder apis.
test=develop

* Add Transformer api.
test=develop

* add unittests for transformer api

* add unittests for transformer api

* Fix some bugs in Transformer apis.
test=develop

* add unittests for encoder, decoder and transformer

* clean conflicts infor in code

* clean Chinese comments

* Add TransformerDecoderCell and TransformerBeamSearchDecoder.
test=develop

* Remove TransformerDecoderCell and TransformerBeamSearchDecoder temporarily.
test=develop

* Add import for Transformer apis.
test=develop

* Update usage of weight_attr and Tensor in Transformer api docs.
test=develop

* Update Transformer apis by renaming MultiheadAttention and cal_kv according to comments.
test=develop

* Fix MultiHeadAttention in test_transformer_api.py.
test=develop
Co-authored-by: NLiuChiaChi <709153940@qq.com>