Feat：memory sdk (#12538)

### What problem does this PR solve?

Move memory and message apis to /api, and add sdk support.

### Type of change

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

sdk/python/ragflow_sdk/__init__.py

@@ -26,6 +26,7 @@ from .modules.session import Session
 from .modules.document import Document
 from .modules.chunk import Chunk
 from .modules.agent import Agent
+from .modules.memory import Memory
 
 __version__ = importlib.metadata.version("ragflow_sdk")
 
@@ -36,5 +37,6 @@ __all__ = [
     "Session",
     "Document",
     "Chunk",
-    "Agent"
+    "Agent",
+    "Memory"
 ]