PluginExtensions: Added onClick to link as a replacement for the command type (#65837)

* Added onClick to the link and made path optional.

* Added type to the import.

* revert(plugin-extensions): put back isPromise utility function

* Minor update to the isPromise function.

* added onClick in the panel menu item.

---------

Co-authored-by: Jack Westbrook <jack.westbrook@gmail.com>
Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

public/app/features/dashboard/utils/getPanelMenu.test.ts

@@ -163,6 +163,31 @@ describe('getPanelMenu()', () => {
       );
     });
 
+    it('should pass onClick from plugin extension link to menu item', () => {
+      const expectedOnClick = jest.fn();
+
+      (getPluginExtensions as jest.Mock).mockReturnValue({
+        extensions: [
+          {
+            pluginId: '...',
+            type: PluginExtensionTypes.link,
+            title: 'Declare incident when pressing this amazing menu item',
+            description: 'Declaring an incident in the app',
+            onClick: expectedOnClick,
+          },
+        ],
+      });
+
+      const panel = new PanelModel({});
+      const dashboard = createDashboardModelFixture({});
+      const menuItems = getPanelMenu(dashboard, panel);
+      const extensionsSubMenu = menuItems.find((i) => i.text === 'Extensions')?.subMenu;
+      const menuItem = extensionsSubMenu?.find((i) => (i.text = 'Declare incident when...'));
+
+      menuItem?.onClick?.({} as React.MouseEvent);
+      expect(expectedOnClick).toBeCalledTimes(1);
+    });
+
     it('should pass context with correct values when configuring extension', () => {
       const panel = new PanelModel({
         type: 'timeseries',

public/app/features/dashboard/utils/getPanelMenu.ts

@@ -291,6 +291,7 @@ export function getPanelMenu(
         extensionsMenu.push({
           text: truncateTitle(extension.title, 25),
           href: extension.path,
+          onClick: extension.onClick,
         });
         continue;
       }