[COMPONENT][Notification] Add event to decide whether local actors should be bothered

components/Notification/Notification.php

@@ -82,12 +82,14 @@ class Notification extends Component
                         continue;
                     }
                 }
+                if (Event::handle('NewNotificationShould', [$activity, $target]) === Event::next) {
                     // TODO: use https://symfony.com/doc/current/notifier.html
                     DB::persist(Entity\Notification::create([
                         'activity_id' => $activity->getId(),
                         'target_id'   => $target->getId(),
                         'reason'      => $reason,
                     ]));
+                }
             } else {
                 // We have no authority nor responsibility of notifying remote actors of a remote actor's doing
                 if ($sender->getIsLocal()) {