feat(customizableOverlay): Add customizable overlay info (#3061)

* overlay customization

* custom overlay definition and examples

* minor fix - import statement difference between cornerstone and cornerstone3D

* move "VOI" and "Zoom" calulation to the ViewportOverlay component, make OverlayItem fairly dull

* type specifications

* follow up fixes for CustomizationService changes on upstream

* [fix] various fixes related to custom overlays (formatting, toggling)

* [fix] various fixes related to custom overlays (formatting, toggling)

* right side overlay panels - align right

* [fix] remove "notification" from toggleOverlay command

* comments

* [refactor] remove unused imports

* documentation of customizable overlay configuration

* prettify

* review of documentation of customization service

* fix useCallback() dependencies

* fix useCallback dependencies

* documentation for customization service

* documentation for customization service

platform/ui/src/components/ViewportOverlay/ViewportOverlay.tsx

@@ -17,7 +17,7 @@ const ViewportOverlay = ({
   bottomLeft,
   color,
 }) => {
-  const overlay = 'absolute pointer-events-none';
+  const overlay = 'absolute pointer-events-none viewport-overlay';
   return (
     <div className={classnames(color ? color : 'text-primary-light')}>
       <div