message: position help icon consistently in top right of screen
diff: </Grid.ColumnDefinitions>
  <TextBlock Margin="20,20,0,0" Style="{StaticResource SubheaderTextBlockStyle}">Format your DAX code</TextBlock>
  - <Button Grid.Column="1" Command="{Binding RefreshCommand}" Style="{StaticResource SubtleButton}" Margin="0,8,24,0">
  + <Button Grid.Column="1" Command="{Binding RefreshCommand}" Style="{StaticResource SubtleButton}" Margin="0,0,24,0">
  <StackPanel Orientation="Horizontal">
  <TextBlock
  FontSize="14"
  </StackPanel>
  </Button>
  - <Button Grid.Column="2" Command="{Binding HelpCommand}" Style="{StaticResource SubtleButton}" Margin="0,8,12,0">
  + <Button Grid.Column="2" Command="{Binding HelpCommand}" Style="{StaticResource SubtleButton}" Margin="0">
  <controls:HelpIcon />
  </Button>
  