feat(ImageOverlayViewerTool): add ImageOverlayViewer tool that can render image overlay (pixel overlay) of the DICOM images (#3163)

Co-authored-by: Joe Boccanfuso <joe.boccanfuso@radicalimaging.com>

platform/core/src/services/ToolBarService/ToolbarService.ts

@@ -265,11 +265,26 @@ export default class ToolbarService extends PubSubService {
       if (!this.buttons[button.id]) {
         this.buttons[button.id] = button;
       }
+      this._setTogglesForButtonItems(button.props?.items);
     });
 
     this._broadcastEvent(this.EVENTS.TOOL_BAR_MODIFIED, {});
   }
 
+  _setTogglesForButtonItems(buttonItems) {
+    if (!buttonItems) {
+      return;
+    }
+
+    buttonItems.forEach(buttonItem => {
+      if (buttonItem.type === 'toggle') {
+        this.state.toggles[buttonItem.id] = buttonItem.isActive;
+      } else {
+        this._setTogglesForButtonItems(buttonItem.props?.items);
+      }
+    });
+  }
+
   /**
    *
    * @param {*} btn