message: Stop Table column header appearing as white in dark mode
diff: <GridView>
  <GridViewColumn Header="" Width="64" x:Name="padding">
  <GridViewColumn.HeaderContainerStyle>
  - <Style TargetType="{x:Type GridViewColumnHeader}">
  - <Setter Property="IsHitTestVisible" Value="False"/>
  + <Style TargetType="{x:Type GridViewColumnHeader}"
  + BasedOn="{StaticResource MahApps.Styles.GridViewColumnHeader}">
  + <Setter Property="IsHitTestVisible" Value="True"/>
  + <Setter Property="IsEnabled" Value="True"/>
  </Style>
  </GridViewColumn.HeaderContainerStyle>
  </GridViewColumn>
  