config flow: import json to reformat cloud response

Because the QueryThingsDataModel comes through as a string attribute
on the json response rather than actual json data, we need to parse
and reformat it to have it readable.

Actually we probably want to condense it with custom formatting, but as a
first step use the json features in Python.

Issue #2419

custom_components/tuya_local/config_flow.py

@@ -1,4 +1,5 @@
 import asyncio
+import json
 import logging
 from collections import OrderedDict
 from typing import Any