[iOS] 시간, 초 표시 포맷팅

fileprivate let formatter: DateComponentsFormatter = {
    var calendar = Calendar.current
    calendar.locale = Locale(identifier: "ko_kr")
    
    let f = DateComponentsFormatter()
    f.calendar = calendar
    f.allowedUnits = [.hour, .minute]
    f.unitsStyle = .full
    return f
}()