* add APIs
* implement save_sharded_model
* add test for hybrid checkpointio
* implement naive loading for sharded model
* implement efficient sharded model loading
* open a new file for hybrid checkpoint_io
* small fix
* fix circular importing
* fix docstring
* arrange arguments and apis
* small fix
* sharded optimizer checkpoint for gemini plugin
* modify test to reduce testing time
* update doc
* fix bug when keep_gatherd is true under GeminiPlugin
* [plugin] torch ddp plugin add save sharded model
* [test] fix torch ddp ckpt io test
* [test] fix torch ddp ckpt io test
* [test] fix low level zero plugin test
* [test] fix low level zero plugin test
* [test] add debug info
* [test] add debug info
* [test] add debug info
* [test] add debug info
* [test] add debug info
* [test] fix low level zero plugin test
* [test] fix low level zero plugin test
* [test] remove debug info
* [checkpoint] support huggingface style sharded checkpoint, to be compatible with hf file naming format
* [checkpoint] support huggingface style sharded checkpoint, to be compatible with hf file naming format
* [checkpoint] Shard saved checkpoint add 'variant' field to customize filename
* [checkpoint] Shard saved checkpoint add 'variant' field to customize filename
* [checkpoint] Shard saved checkpoint add 'variant' field to customize filename
* [checkpoint] Shard saved checkpoint add 'variant' field to customize filename
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Co-authored-by: luchen <luchen@luchendeMacBook-Pro.local>
Co-authored-by: luchen <luchen@luchendeMBP.lan>
Baizhou Zhang