Wait for user allowlisting to apply before reloading the website (#2515)

The popup UI (e.g. privacy dashboard) lets users disable protections
for a website. When the user clicks the toggle button, the website is
allowlisted and reloaded. With MV3, this requires a
declarativeNetRequest rule update which doesn't happen instantly. We
need to take care for that rule update to finish before reloading the
page, because otherwise some requests might still be blocked after the
reload.

shared/js/background/message-handlers.js

@@ -50,8 +50,11 @@ export function setList (options) {
  * @param {import('@duckduckgo/privacy-dashboard/schema/__generated__/schema.types').SetListOptions} options
  */
 export async function setLists (options) {
+    // TODO: Consider making these tabManager.setList calls concurrently with
+    //       Promise.all, but first verify that works in practice (e.g. with
+    //       simultaneous DNR rule updates).
     for (const listItem of options.lists) {
-        tabManager.setList(listItem)
+        await tabManager.setList(listItem)
     }
 
     try {