[bug] Close fragment notification if we're in the same page

[nemesifier]

Describe the bug

When clicking on a notification that redirects to a page fragment, the behavior looks buggy when we're already in the target page.

Steps To Reproduce

1. Trigger a fragment notification
2. Click on "open"
3. Once the page has loaded, open the notification again and click on "open" again

Result: notification overlay stays open.

Expected behavior

Notification overlay closes.

If we detect we're already in the target page (with JS) we should close the notification overlay.