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

openai_pandasai_service.py

@@ -260,6 +260,7 @@ def openai_chart(csv_url: str, question: str):
             answer = df.chat(question + instructions)
             
             if process_answer(answer):
+                print("OpenAI API error", answer)
                 return "Chart not generated"
             return answer