No confirmation message when adding new redirect

[whyleee]

Hi! We've successfully updated from the old handler version to Optimizely CMS12 version. But editors complain they don't see a confirmation message when adding new redirects. Such message was displayed earlier and now it is more confusing whether the action finished with success.

Steps to reproduce:

1. Go to NotFound handler Redirects section
2. Set the Old URL, the New URL and click the Add button

Expected: redirect is added and a confirmation message is displayed that the operation is successful

Actual: redirect is added, but no visible status is displayed in UI