Clear notifications for fully read rooms using the event's timestamp instead of delivery date

NSE/Sources/NotificationContentBuilder.swift

@@ -33,6 +33,7 @@ nonisolated struct NotificationContentBuilder {
         switch notificationItem.event {
         case .timeline(let event):
             notificationContent.eventID = event.eventId()
+            notificationContent.eventDate = Date(timeIntervalSince1970: TimeInterval(event.timestamp()) / 1000)
         case .invite, .none:
             notificationContent.eventID = nil
         }