create and update dataset (#2110)

### What problem does this PR solve?

Added the ability to create and update dataset for SDK

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: root <root@xwg>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

sdk/python/ragflow/__init__.py

@@ -3,3 +3,4 @@ import importlib.metadata
 __version__ = importlib.metadata.version("ragflow")
 
 from .ragflow import RAGFlow
+from .modules.dataset import DataSet