feat: Add optional notification email when invite is accepted (#3718)

* feat: Add optional notification email when invite is accepted

* Refactor to use beforeSend

app/scenes/Settings/Notifications.tsx

@@ -44,6 +44,13 @@ function Notifications() {
         "Receive a notification whenever a new collection is created"
       ),
     },
+    {
+      event: "emails.invite_accepted",
+      title: t("Invite accepted"),
+      description: t(
+        "Receive a notification when someone you invited creates an account"
+      ),
+    },
     {
       visible: isCloudHosted,
       event: "emails.onboarding",