private void BtnEditSelected_Click(object sender, RoutedEventArgs e)
        {
            var window = new AddCredentials(true, LstEntries.SelectedIndex);

            window.ShowDialog();
        }
        private void BtnAddCredentials_Click(object sender, RoutedEventArgs e)
        {
            var window = new AddCredentials(false);

            window.ShowDialog();
        }