Refactor response handling and centralize JSON configuration

Replaced direct fields in `AbstractResponse` with `ResponseResultInfo` for better encapsulation and consistency. Introduced `JsonConf` to provide a shared, reusable `ObjectMapper` configuration. Updated tests and logic to align with the refactored response structure, enhancing maintainability and readability.

src/test/resources/error-response.json

@@ -0,0 +1,11 @@
+{
+  "result": null,
+  "success": false,
+  "errors": [
+    {
+      "code": 81053,
+      "message": "An A, AAAA, or CNAME record with that host already exists. For more details, refer to \u003chttps://developers.cloudflare.com/dns/manage-dns-records/troubleshooting/records-with-same-name/\u003e."
+    }
+  ],
+  "messages": []
+}