constructor(parent) {
    super(parent)

    // Material Icons font URL
    this.font = 'https://fonts.gstatic.com/s/materialicons/v36/flUhRq6tzZclQEJ-Vdg-IuiaDsNa.woff'
  }
Convenience class for displaying icons using the Material Icons library. See https://material.io/icons/

Use this just like any other UIBlock3DFacade, but set its `icon` property to the name of the icon
you wish to display.

Note: internally this simply sets the 'text' property, using the Material Icons web font. Since that
font utilizes ligatures to alias each icon's full name to its glyph, and Troika's text rendering engine
has support for ligatures, this just works without having to deal with obscure character codes.