* support zero for expert local dp
* fix above codes:
*treat optim.zero_world_size and optim.zero_local_rank as list in model_checkpoint.py and test_model_checkpoint.py
*add overlap and zero check for moe in args_sanity_check(.)
* fix(ckpt): ckpt bug fix and api refactor
1. fix latest ckpt query bug
2. add ckpt unit test
3. fix storage manager boto3/local client get_fns bug
4. fix only model load case zero fp32 buffer overwrite model weights bug.
5. add ckpt_type and add zero reload ci-test
* fix(ckpt): fix ckpt and trainer bug
* fix and refactor
* fix base on comment
* feat: add legacy api
Wenwen Qu