fix: Backend crashes when invalid url is used

Improve error handling for flow info API

backend/src/restful/response.js

@@ -0,0 +1,18 @@
+export function success(resp, data, statusCode) {
+    resp.status(statusCode || 200).json({
+        status: 'success',
+        data,
+    });
+}
+
+export function failed(resp, error, statusCode) {
+    resp.status(statusCode || 500).json({
+        status: 'failed',
+        error: {
+            code: error.code,
+            type: error.type,
+            message: error.message,
+            details: error.details,
+        },
+    });
+}