fix(viewports): The display of linked viewports during drag and drop has a race (#3286)

* fix: The display of linked viewports during drag and drop has a race

* PR review comments

* fix: Segmentation display two up

* Removing console logs

* Fix the blank viewport can have stuff added to it

* Fix the null name on HP module

* Fix the navigate to initial image

* Fix the nth interleave loader

* Fix the unit tests

* PR comments - docs mostly

* fix: Exception thrown on change displayset after double click

platform/core/src/extensions/ExtensionManager.test.js

@@ -206,40 +206,40 @@ describe('ExtensionManager.ts', () => {
       const extension = {
         id: 'hello-world',
         getViewportModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getSopClassHandlerModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getPanelModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getToolbarModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getCommandsModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getLayoutTemplateModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getDataSourcesModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getHangingProtocolModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getContextModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getUtilityModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getCustomizationModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
         getStateSyncModule: () => {
-          return [{}];
+          return [{ name: 'test' }];
         },
       };