[Random Generator] Part1: Dev random generator (#5360)

* 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

* Refine code style (#5375)

* fix unordered map: enum class not hashable

* roll back to unordered map

Co-authored-by: Houjiang Chen <chenhoujiangcug@gmail.com>