feat: add GraphRAG framework and integrate TuGraph (#1506)

Co-authored-by: KingSkyLi <15566300566@163.com>
Co-authored-by: aries_ckt <916701291@qq.com>
Co-authored-by: Fangyin Cheng <staneyffer@gmail.com>

dbgpt/rag/transformer/base.py

@@ -0,0 +1,26 @@
+"""Transformer base class."""
+import logging
+from abc import ABC, abstractmethod
+from typing import List, Optional
+
+logger = logging.getLogger(__name__)
+
+
+class TransformerBase:
+    """Transformer base class."""
+
+
+class EmbedderBase(TransformerBase, ABC):
+    """Embedder base class."""
+
+
+class ExtractorBase(TransformerBase, ABC):
+    """Extractor base class."""
+
+    @abstractmethod
+    async def extract(self, text: str, limit: Optional[int] = None) -> List:
+        """Extract results from text."""
+
+
+class TranslatorBase(TransformerBase, ABC):
+    """Translator base class."""