* [legacy] move communication to legacy (#4640)
* [legacy] refactor logger and clean up legacy codes (#4654)
* [legacy] make logger independent to gpc
* [legacy] make optim independent to registry
* [legacy] move test engine to legacy
* [legacy] move nn to legacy (#4656)
* [legacy] move nn to legacy
* [checkpointio] fix save hf config
* [test] remove useledd rpc pp test
* [legacy] fix nn init
* [example] skip tutorial hybriad parallel example
* [devops] test doc check
* [devops] test doc check
Hongxin Liu