add save cache model api in fleet& add slots shuffle in dataset module & add metric op to calculate ctr related metrics (#18871)

* add ctr related metric layer test=develop

* add save cache and slots shuffle test=develop

* add save cache and slots shuffle test=develop

* fix error

* fix error

* fix style for ci

* fix for comments

* change SlotsShuffle input to std::strinf for generality

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix stylr

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* fix style

* change non-const reference to pointer

* fix style

* fix style

* fix style test=develop

* fix style  test=develop

* add return ins num in ctr metric op

* change dtype to float in metric_op.py

* fix error test=develop

* fix style test=develop

* fix API spec

* fix API spec

* fix API spec test=develop

* add UT test=develop

* add a place field in DataFeed to denote which place it will feed data to.
* abstract the copy process in CopyToFeedTensor function
* add UT for float32 type and for CUDAPlace

（1）support patch data （merge slots of instances of same line id, modify dense layer which
changes its size）
（2）add fleet load_one_table interface, support load from paddle model and load from pslib model
（3）fix push sparse bug which cause push sparse cost more time（about 10% in my testcase）
（4）when some slots are not in one of your network (join/update, etc.)，data feed、collect label info、push/pull sparse will skip these slots， instead of throw error.
（5）add more debug info in TrainFilesWithProfiler

* remove async executor and add data_feed.proto to the deps of train demo

(1) use channel instead of vector/BlockingQueue in Dataset，to keep same with existing implementation, and make code more readable and flexible (dataset single output channel or multi output channel). one previous memory out of limit problem is cause by not release memory after training.
(2) add Record because MultiSlotType costs too much memory (80B)，fix memory out of limit problem.
(3) add Channel, Archive in paddle/fluid/framework
(4) change dataset from shared_ptr to unique_ptr in pybind
(5) move create/destroy readers from trainer to dataset
(6) move shuffle from datafeed to dataset. dataset holds memory, datafeed is only for load data and feed data to network.
(7) fix thread num bug of Dataset when filelist size < thread num
(8) support set_queue_num in InMemoryDataset

Add Pipeline Concurrency Train Mode:
- Cpp: pipeline_trainer & section_worker
- Python: PipelineOptimizer
- Add a new data_feed type: PrivateInstantDataFeed
- Add a test demo of pipeline trainer and the test model is gnn
- Do not support win32 now

* add save/load model, shrink table, cvm, config file & fix pull dense bug
test=develop

* fix global shuffle bug, fix pull dense bug, fix release memeory bug, fix shrink error
add client flush, add get data size
test=develop

* fix global shuffle bug
test=develop

* fix global shuffle bug
test=develop

* fix code style
test=develop

* fix code style & modify pslib cmake
test=develop

* fix error of _role_maker
test=develop

* fix code style
test=develop

* fix code style
test=develop

* fix code style
test=develop

* fix code style
test=develop

* fix code style
test=develop

* fix windows compile error of fleet
test=develop

* fix global shuffle bug

* add comment
test=develop

* update pslib.cmake
test=develop

* fix fill sparse bug
test=develop

* fix push sparse bug
test=develop

* fix train_from_dataset and infer_from_dataset example

* add inductive dim for data_reader, example: shape=[-1, 1], then -1 will be inducted through run-time reading of number of elements

test=develop

test=develop

test=develop

test=develop

test=develop

test=develop

dataset_generator.py is a framework for generating data with python
the generated data with a fixed format will be feeded into c++ reader
test=develop

test=develop

* AsyncExecutor: C++ side

* Google naming conventions

* Rename MultiExecutor to AsyncExecutor

* pybind with async_executor

* Naming convention

* remove some flags and unused code

* add refactored file of async_executor and data_feed

* clear async executor interface and add data feed factory

* split async executor into executor_thread_worker and async_executor, refactor pybind, add datafeed and corresponding proto

* Fix async_executor interfaces: 1) Remove all protobufs; 2) Stop after each epoch

* refine async_executor_refactor.cc

* add some files about datafeed

* Revert "add some files about datafeed"

This reverts commit 8ee8133a.

* Interface rework

* add MultiSlotDataFeed

* Creating DataFeedDesc from .proto file, then manipulate it (add/del fields etc) from python side

* update data_feed for add MultiSlotDataFeed

* update datafeed and async_executor to run bow_net demo

* fix bug that finish_set_filelist failed in multithread

* delete finish_binding_memory_(flag), because it can not be marked under the current interface

* Fix bug

* update async_executor.py for support set_use_slots

* update async_executor.py for support set_use_slots and set set_dense_slots

* fix bug that when the number of files is less than the number of threads, it will fetch nan

* remove redundant code, and make executor exit when set a illegal queue size

* add batch_size check

* add MultiSlotDesc

* Revert "add MultiSlotDesc"

This reverts commit 2e72ebfa.

* add some checkpoint in DataFeedDesc

* add CheckFile function in MultiSlotDataFeed

* update something error info

* fix deaded lock bug

* Fix fetch variable

* Merge error

* fix code style in async_executor

* using one lock blocking queue replace two lock blocking queue because of some bugs

* update code style

* add utest for data_feed

* Fix fetch var

* update utest for data_feed for multithread

* update SetFileList info

* fix bug in utest of data_feed

* Add comments for python

* Add comments for python code

* Fix pybind.cc with new pybind11 version

* add note for DataFeedDesc's set_use_slots function

* Add save_model

* update data_feed_test for multi-type

* add comment for executor_thread_worker

* Remove unused code

* update data_feed_test for generate test data file

* removed unnecessary interfaces and add comments

* c++ style check

* update data_feed.cc

* AsyncExecutor: C++ side

Google naming conventions

Rename MultiExecutor to AsyncExecutor

pybind with async_executor

Naming convention

remove some flags and unused code

add refactored file of async_executor and data_feed

clear async executor interface and add data feed factory

split async executor into executor_thread_worker and async_executor, refactor pybind, add datafeed and corresponding proto

Fix async_executor interfaces: 1) Remove all protobufs; 2) Stop after each epoch

refine async_executor_refactor.cc

add some files about datafeed

Revert "add some files about datafeed"

This reverts commit 8ee8133a.

add MultiSlotDataFeed

Interface rework

Creating DataFeedDesc from .proto file, then manipulate it (add/del fields etc) from python side

update datafeed and async_executor to run bow_net demo

update async_executor.py for support set_use_slots

Fix bug

update async_executor.py for support set_use_slots and set set_dense_slots

fix bug that when the number of files is less than the number of threads, it will fetch nan

remove redundant code, and make executor exit when set a illegal queue size

add MultiSlotDesc

Revert "add MultiSlotDesc"

This reverts commit 2e72ebfa.

add some checkpoint in DataFeedDesc

Fix fetch variable

fix code style in async_executor

Fix fetch var

add utest for data_feed

Add comments for python

update utest for data_feed for multithread

fix bug in utest of data_feed

Add comments for python code

Fix pybind.cc with new pybind11 version

add note for DataFeedDesc's set_use_slots function

update data_feed_test for multi-type

Add save_model

update data_feed_test for generate test data file

removed unnecessary interfaces and add comments

add comment for executor_thread_worker

Remove unused code

update data_feed.cc

c++ style check

* commit for code style

* commit for code style

* commit for code style

* commit for code style

* Comment away __init__ in async_executor.py

* clang-format fix test=develop

* use PADDLE_THROW instead of exit(-1); use unique_ptr to manage scope var in data_feed_test.cc

* commit for update code style

* commit for update code style

* Add async_executor demo; Remove some methods
test=develop

* commit for update code style

* commit for update code style

* commit for update code style

* update API.spec

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* Fix API.spec
test=develop

* Fix API.spec
test=develop

* Fix windows build error
test=develop

* FIx windows build error
test=develop

* FIx windows build error
test=develop

* FIx windows build error
test=develop

* Fix Windows Build
test=develop

* Fix Windows Build
test=develop

* Fix Windows Build
test=develop

* Fix code style
test=develop

* Fix code style
test=develop

* update datafeed

* Fix code style
test=develop

* update data_feed_test for test Tensor test=develop

* Fix code style
test=develop

* Fix windows build failure
test=develop

* Fix code style and windows build failure
test=develop

* Fix PYTHON3.5 build failure
test=develop

* AsyncExecutor API
test=develop