GitLab

* implement sharded optimizer saving

* add more param info

* finish implementation of sharded optimizer saving

* fix bugs in optimizer sharded saving

* add pp+zero test

* param group loading

* greedy loading of optimizer

* fix bug when loading

* implement optimizer sharded saving

* add optimizer test & arrange checkpointIO utils

* fix gemini sharding state_dict

* add verbose option

* add loading of master params

* fix typehint

* fix master/working mapping in fp16 amp