fix(argus.client.base): verify response parameters in check_response

This fixes an issue where backend replies with non-standard exception
(can happen when such exception is unhandled on the backend side).

argus/client/base.py

@@ -59,9 +59,10 @@ def check_response(response: requests.Response, expected_code: int = 200):
         response_data: JSON = response.json()
         LOGGER.debug("API Response: %s", response_data)
         if response_data.get("status") != "ok":
+            exc_args = response_data["response"]["arguments"]
             raise ArgusClientError(
                 f"API Error encountered using endpoint: {response.request.method} {response.request.path_url}",
-                response_data["response"]["arguments"][0],
+                exc_args[0] if len(exc_args) > 0 else response_data.get("response", {}).get("exception", "#NoMessage"),
             )
 
     def get_url_for_endpoint(self, endpoint: str, location_params: dict[str, str] | None) -> str: