* topo and memory performance for heterps; test=develop
* add trainwithprofiler in heter trainier; test=develop

* update, test=develop

* fix entry

* fix distributed lookup table fuse case

* fix entry bug at first time

* move entry from paddle.fluid -> paddle.distributed

* fix ut with paddle.enable_static()
Co-authored-by: Nmalin10 <malin10@baidu.com>

* test=develop, save/load, shrink
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

* Fix the bug in fleet amp_init.

* Fix the amp_init unit test.

* add fleet amp.init()

* add unittest for fleet_amp_init

* update, test=develop

* add trainers for pserver

Change-Id: I1a75793ec81ce126d07f4c47cae09b95d530bbc8

* test=develop, fix fleet.metrics(mse, rmse, mae)

Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

* test=develop, add distributed_infer

* rename sendrecv.proto to namespace paddle.distributed

* split ps with distributed

* add save tensor support
Co-authored-by: NseiriosPlus <tangwei12@baidu.com>

* add tensor table

* update, test=develop

* update, test=develop

* oneps (3/4)
Co-authored-by: NMrChengmo <cmchengmo@163.com>
Co-authored-by: Nmalin10 <malin10@baidu.com>
Co-authored-by: Nchengmo <chengmo@baidu.com>

* fix fleet for multi-stream

* fix memcpy for ncclid

* use sync to solve move operation

* Sharding add hybrid-dp feature

* update sharding in distributed_strategy

* update sharding unitest

* revise code format for sharding

* add tensor_indices in AssignGroupBySize

* add rebuild group in reducer

* update, test=develop

* fix doc, test=document_fix

* fix fleet api doc

* test=develop, rm pathlib

* add reducer

* refine envent for memorycopy

* add concat&split for allreduce

* apply concat & split for fuse tensor

* fix nccl dep

* fix the untest, compile problem and ddp initialize problem

* fix untest for mac & add some comments & solve the repeated param in sublayers

* fix untest for windows & fix document