remove hard coded usage of phet.joist.display in speakerHighlighter.js, https://github.com/phetsims/joist/issues/686  https://github.com/phetsims/scenery-phet/issues/670
remove hard coded usage of phet.joist.display in speakerHighlighter.js, https://github.com/phetsims/joist/issues/686  https://github.com/phetsims/scenery-phet/issues/670

phetsims/scenery-phet,phetsims/scenery-phet,phetsims/scenery-phet