Compatible single client (#5417)

* mkdir compatible/single_client

* mv to compatible/singe_client/python

* mv to ./python/compatible/

* use oneflow.compatible.single_client

* back up

* backup

* refactor oneflow.xxx to oneflow.compatible.single_client.xxx

* mv to single_client

* refactor import oneflow to oneflow.compatible.single_client

* backup

* refine

* refine

* make single_clint ci test copy from correct path

* refine

* refine

* delete ioconf and split single-clint ci test

* auto format by CI

* delete default session

* fix method of erase sess id

* delete string multi client in test.yml

* fix spell error

* delete space

* refine

* mv single client python file to compatible_single_client_python

* refine

* fix ci error

* fix bug

* fix bug

* refine

* refine

* delete skip if in test/(modules/tensor)/* because of default eager env

* fix bug

* synchronization oneflow/compatible_single_client and oneflow/python

* fix distributed_run bug

* fix test_multi_process dead lock

* fix test_multi_process dead lock

* synchronization modify between oneflow/python and oneflow/compatible_single_client

* refine

* minor fix

* fix bug

* fix doctest.sh

* rm files

* remove files and add checks

* delete moduels

* Revert "delete moduels"

This reverts commit f95ab369f556b71fd0663b67c6dd51c9b6d5ee81.

Co-authored-by: Xinqi Li <lixinqi0703106@163.com>
Co-authored-by: liufengwei <2472937968@qq.com>
Co-authored-by: oneflow-ci-bot <ci-bot@oneflow.org>
Co-authored-by: oneflow-ci-bot <69100618+oneflow-ci-bot@users.noreply.github.com>
Co-authored-by: tsai <jackalcooper@gmail.com>