Scale Overlay Tool
How to set up the ScaleOverlay tool:
// Init cornerstone tools
cornerstoneTools.init();
// Enable any elements, and display images
// ...
// Add our tool, and set it's mode
const ScaleOverlayTool = cornerstoneTools.ScaleOverlayTool;
cornerstoneTools.addTool(ScaleOverlayTool)
cornerstoneTools.setToolActive('ScaleOverlay', { mouseButtonMask: 1 })