Allow useWidgetAPI to not actually send a request

src/utils/proxy/use-widget-api.js

@@ -7,7 +7,11 @@ export default function useWidgetAPI(widget, ...options) {
   if (options && options[1]?.refreshInterval) {
     config.refreshInterval = options[1].refreshInterval;
   }
-  const { data, error, mutate } = useSWR(formatProxyUrl(widget, ...options), config);
+  let url = formatProxyUrl(widget, ...options)
+  if (options[0] === "") {
+    url = null
+  }
+  const { data, error, mutate } = useSWR(url, config);
   // make the data error the top-level error
   return { data, error: data?.error ?? error, mutate }
 }