* add heter ps mode

* code style
test=develop

* add with_pslib
test=develop

* unitest
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* code style
test=develop

* test monitor
test=develop

* prepare trainer
test=develop

* code style
test=develop

fix invalid read of pnorm gradient function and delete the unused code

Add dgc to fleet meta optimizer, rm dgc from optimizer all

* cunn8 support
test=develop

* fix ci error
test=develop

test=develop

* Add some error messages for the op without double grads.

* fix the test_imperative_double_grad UT.

* add fleetrun command for distributed running; test=develop

* develop dynamic shape serilization

* add test param for gelu

* fix bugs

* delete redundant comments

* debug

* fix conflict. test=develop

* fix bug. test=develop

* add trt dynamic shape serialized support

* fix ernie serialized bug
test=develop

* fix codestyle
test=develop

* fix bug
test=develop

* fix bug.test=develop

* modify cmakelist test=develop

* fix bug
test=develop

* fix error message.  test=develop

* fix trt register plugin based on pr#25003

* add trt dynload

* fix deserialization bug of not finding plugin registration

* refine code style

* recover engine key in tensorrt_subgraph_pass

* for ci coverage

* add unittest for deserialization
Co-authored-by: Nhaozech <chenhaoze94@gmail.com>

Update the code for the compare ops for the broadcast function

* disable heart beat UT

* fix dump, fix cvm check
test=develop

* fix
test=develop

* fix
test=develop

* fix
test=develop

* split meta optimizer files
* add graph execution in execution, update two properties in DistributedStrategy, unit tests for these features

* fix inverse bug, test=develop

* fix the untest, test=develop

* add singular checking, test=develop

* fix the utest, test=develop

* use memory::copy, test=develop

* fix bost_get, test=develop

* fix position, test=develop

* polish framework error message part 4

* fix type error

* fix message error

* polish by review comments

* modify GetExpectedKernelType

* use input place

* add ENFORCE check

Update the code for the compare_ops, update the api and doc 

* bug fix, test=develop

* fix windows test
test=develop

* fix ci
test=develop

* fix test_pipeline, test=develop

* refine error stack format

* polish compile traceback format

* polish detail format

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

* Integrated Trainer of Parameter Server

* fix double grad visitid unit; test=develop

* change name hash_pair to HashPair; test=develop

* follow comment; test=develop

* Remove the output for moving_average_abs_max_scale op, test=develop

* refine strategy compiler and meta optimizers
make async as a_sync

* unified signal error format

* refine signal error message

* remove ProgramTranslator.save_inference_model

* adapt save_quantized_model

* revert buffer check implemention

* remove useless import function

* simplify buffered reader to improve DataLoader performance

* fix 22 failed unittests

* fix cuda pinned context condition

* fix test_reader_reset failed

* fix two failed unittests

* change unittest place

* polish error messaage

* polish cast op GetExpecctedKernelType

* remove debug info in unittest