[Random Generator] Part2: Migrate functional dropout (#5378)

* add random generator

* reformat

* refactor: allow auto generator

* refactor: remove kAUTO, update python api and test

* refactor: use member initializer lists, fix build issue when cpu only

* handle exeception given invalid device

* add dropout functor; add OpExprInterpContext; refactor random_mask_like based on random_generator

* refactor random generator

* disable generator's copyandmove constructor

* reformat

* fix bad merge

* refine

* fix cpu only build

* auto format by CI

* refactor

* use global generator when no generator specified in functional api

* refine

Co-authored-by: oneflow-ci-bot <ci-bot@oneflow.org>
Co-authored-by: Houjiang Chen <chenhoujiangcug@gmail.com>
Co-authored-by: oneflow-ci-bot <69100618+oneflow-ci-bot@users.noreply.github.com>