HTML Widgets; Grid Visualiser; Chart forces screen to scroll if window area is taller than it is wide

The HTML Widget Grid Visualiser (used on the Visualisation tab of various Task Manager 2 folders) did not restrict the grid's width to the available area. It assumed the screen area would always be wider than it was tall. This has been updated so that, instead of scrolling horizontally, the chart will resize to fit the available area.