* open header for custom kernel

* add core utils

* tidy core code

* tify header

* tidy include

* tidy namespace

* resolve conflit

* fix unittest and coverage

* remove platform using

* resolve conflict

* resolve conflict

* fix digamma namespace error

* fix xpu full kernel error

* fix xpu full kernel error

* polish details

* add place for lib storage

* updates callers, test=develop

* updates tensor, test=develop

* fixes errors, test=develop

* remove some dtypes, test=develop

* fix errors in the base storage modification, test=develop

* fixes a bug, test=develop

* fixes the bugs in push the whole, test=develop

* updates, test=develop

* update

* update, test=develop

* fixes the mac-py3 CI, test=develop

* remove the storage impl, test=develop

* updates some codes, test=develop

* update, test=develop

* updates pten allocation, test=develop

* Migrate Dim and DDim from paddle::framework into pten namespace

* fix paddle::framework::Array

* fix framework::Array

* add empty and empty_like kernel in pten

* add empty dev_api