message: Make selected date semibold (win)
diff: <Trigger Property="IsSelected" Value="True">
  <Setter TargetName="SelectedBackground" Property="Opacity" Value="1" />
  <Setter TargetName="NormalText" Property="TextElement.Foreground" Value="White" />
  + <Setter TargetName="NormalText" Property="TextElement.FontWeight" Value="SemiBold" />
  </Trigger>
  <MultiDataTrigger>
  <MultiDataTrigger.Conditions>
  <Setter TargetName="DayButtonFocusVisual" Property="Stroke" Value="{DynamicResource Toggl.SecondaryTextBrush}" />
  <Setter TargetName="DayButtonFocusVisual" Property="Visibility" Value="Visible" />
  <Setter TargetName="NormalText" Property="TextElement.Foreground" Value="White" />
  + <Setter TargetName="NormalText" Property="TextElement.FontWeight" Value="SemiBold" />
  </MultiDataTrigger>
  <MultiDataTrigger>
  <MultiDataTrigger.Conditions>
  