message: Implement close button for in-app notification (win)
diff: <StackPanel Background="#06AAF5">
  <Button x:Name="closeButton"
  Height="20" Width="20"
  + Background="Transparent"
  + BorderThickness="0"
  HorizontalAlignment="Right"
  VerticalAlignment="Top"
  Foreground="White"
  - Click="CloseButton_OnClick">X</Button>
  + Click="CloseButton_OnClick">
  + <Button.Style>
  + <Style BasedOn="{StaticResource {x:Type Button}}" TargetType="Button">
  + <Style.Triggers>
  + <Trigger Property="IsMouseOver" Value="True">
  + <Setter Property="Background" Value="#33FFFFFF" />
  + <Setter Property="Cursor" Value="Hand" />
  + </Trigger>
  + <Trigger Property="IsPressed" Value="True">
  + <Setter Property="Background" Value="#66FFFFFF" />
  + </Trigger>
  + </Style.Triggers>
  + </Style>
  + </Button.Style>
  +
  + <Image Source="/TogglDesktop;component/Resources/ic_close_white600_36dp.png"
  + Height="20" VerticalAlignment="Top" />
  + </Button>
  <TextBlock Text="{Binding ElementName=me, Path=Title}"
  FontWeight="Bold"
  TextWrapping="Wrap"
  