* 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