[Feature]Use Megatron-core dist_checkpointing to load checkpoint with different parallel strategies

[SeaOfOcean]

Is your feature request related to a problem? Please describe.
Currently ChatLearn use a tool to convert checkpoint when different parallel strategies are detected, https://github.com/alibaba/ChatLearn/blob/main/chatlearn/utils/megatron_utils.py#L164

The online conversion has been addressed in Megatron core dist_checkpointing. https://docs.nvidia.com/megatron-core/developer-guide/latest/api-guide/dist_checkpointing.html

Describe the solution you'd like
Use Megatron-core dist checkpointing to save and load checkpoint.