call services from API instead of adapters

src/text_generation/services/language_models/retrieval_augmented_generation_response_service.py

@@ -0,0 +1,14 @@
+from src.text_generation.adapters.llm.language_model_with_rag import LanguageModelWithRag
+from src.text_generation.services.language_models.abstract_language_model_response_service import AbstractLanguageModelResponseService
+
+
+class RetrievalAugmentedGenerationResponseService(AbstractLanguageModelResponseService):
+
+    def invoke(self, user_prompt: str) -> str:
+
+        if not user_prompt:
+            raise ValueError(f"Parameter 'user_prompt' cannot be empty or None")
+
+        rag = LanguageModelWithRag()
+        response = rag.invoke(user_prompt=user_prompt)
+        return response