Follow-up to T208777: Factor notification-related methods out of User and Title, introduce WatchlistNotificationManager
- Uses of Title::getNotificationTimestamp - https://codesearch.wmflabs.org/deployed/?q=-%3EgetNotificationTimestamp%5C(&i=nope&files=&repos=
- Uses of User::clearNotification - https://codesearch.wmflabs.org/deployed/?q=-%3EclearNotification%5C(&i=nope&files=&repos=
- Uses of User::clearAllNotifications - https://codesearch.wmflabs.org/deployed/?q=-%3EclearAllNotifications%5C(&i=nope&files=&repos=