frontend: Don't prefix the request error messages

Instead of prefixing the requests' error messages with "Api request
error", just use the error's own message because the UI may want to
prefix it in a different way.

frontend/src/lib/k8s/apiProxy.ts

@@ -74,7 +74,7 @@ export async function request(path: string, params: RequestParams = {},
       logout();
     }
 
-    let message = `Api request error: ${statusText}`;
+    let message = statusText;
     try {
       const json = await response.json();
       message += ` - ${json.message}`;