Dump raw JSON messages (#1080)

This amends the helper that dumps the requests to dump the JSON as
represented by the models instead of a printable representation of the
models.

Author: jhrozek

src/codegate/providers/base.py

@@ -246,6 +246,10 @@ def _dump_request_response(self, prefix: str, data: Any) -> None:
 
             with open(fname, "w") as f:
                 json.dump(data, f, indent=2)
+        elif hasattr(data, "json"):
+            # The new format
+            with open(fname, "w") as f:
+                f.write(data.json())
         else:
             with open(fname, "w") as f:
                 f.write(str(data))