feat: Add extensibility for tmtv and segmentation modes (#6128)

* feat: Add extensibility for tmtv and segmentation modes

* Fixes for ordering issues on laod

* Remove unnecessary reference lookup

* Chane side panel timing to fix tests

* PR comments - change how mode definitions get created

* Improvements to mode customizations

* Start organizing customizations

* Misc fixes for a customization demo page

* Security fixes

* PR requested changes to naming

tests/Customization.spec.ts

@@ -4,7 +4,7 @@ test('should apply customization from URL query parameter', async ({ page }) =>
   const studyInstanceUID = '2.25.96975534054447904995905761963464388233';
 
   await visitStudyOptions(page, studyInstanceUID, {
-    customization: 'veterinaryOverlay',
+    customization: 'veterinary/veterinaryOverlay',
   });
 
   const patientNameOverlayItem = page