Search for script files in nested directories (#15457)

* Search for script files in nested directories

* Add script files

* oops

src/notebooks/controllers/ipywidgets/scriptSourceProvider/baseIPyWidgetScriptManager.unit.test.ts

@@ -75,6 +75,12 @@ suite('ipywidget - CDN', () => {
             config: {
                 'js-logger': 'https://unpkg.com/js-logger/src/logger.min'
             }
+        },
+        {
+            file: '@finos/perspective-jupyterlab',
+            config: {
+                '@finos/perspective-jupyterlab': 'nbextensions/@finos/perspective-jupyterlab/index'
+            }
         }
     ].forEach((item) => {
         test(`Extract require.js configuration mapping for ${item.file}`, async () => {

src/notebooks/controllers/ipywidgets/scriptSourceProvider/localIPyWidgetScriptManager.node.ts

@@ -114,7 +114,7 @@ export class LocalIPyWidgetScriptManager extends BaseIPyWidgetScriptManager impl
 
         // Get all of the widget entry points, which would be of the form `nbextensions/<widget folder>/extension.js`
         const nbExtensionsFolder = Uri.joinPath(nbExtensionsParentPath, 'nbextensions');
-        const extensions = await this.fs.searchLocal('*/extension.js', nbExtensionsFolder.fsPath, true);
+        const extensions = await this.fs.searchLocal('**/extension.js', nbExtensionsFolder.fsPath, true);
         return extensions.map((entry) => ({
             uri: Uri.joinPath(nbExtensionsFolder, entry),
             widgetFolderName: path.dirname(entry)