modifies orchestrator,add code_exec tool, openai_chat (later we add chat)

orchestrator_functions.py

@@ -519,7 +519,7 @@ async def csv_chat(csv_url: str, query: str):
             )
             logger.info("LangChain-Gemini answer:", gemini_answer)
             
-            if not process_answer(gemini_answer) or gemini_answer is None:
+            if gemini_answer is not None:
                 return {"answer": jsonable_encoder(gemini_answer)}
             
             raise Exception("LangChain-Gemini response not usable, falling back to LangChain-Groq")
@@ -534,7 +534,7 @@ async def csv_chat(csv_url: str, query: str):
                 )
                 logger.info("LangChain-Groq answer:", lang_groq_answer)
                 
-                if not process_answer(lang_groq_answer):
+                if lang_groq_answer is not None:
                     return {"answer": jsonable_encoder(lang_groq_answer)}
                 
                 raise Exception("LangChain-Groq response not usable, falling back to raw Groq")