Add UTF-8 json ouput support while langchain.debug is set to True. (#5802)

Before:
<img width="984" alt="image"
src="https://github.com/hwchase17/langchain/assets/4317474/2b0807b4-a1d6-4df2-87cc-92b1c8e10534">

After:
<img width="992" alt="image"
src="https://github.com/hwchase17/langchain/assets/4317474/128c2c7d-2ed5-4c95-954d-b0964c83526a">


Thanks in advance.

 @agola11

langchain/callbacks/tracers/stdout.py

@@ -8,7 +8,7 @@ from langchain.input import get_bolded_text, get_colored_text
 
 def try_json_stringify(obj: Any, fallback: str) -> str:
     try:
-        return json.dumps(obj, indent=2)
+        return json.dumps(obj, indent=2, ensure_ascii=False)
     except Exception:
         return fallback