Dashboards: Add restricted extension point for empty state (#111788)

* Dashboards: Add restricted extension point for empty state

* FeatureToggles: Regenerate files with new toggle

* Dashboards: Pass default empty UI as component, not children

* Dashboards: Expose hooks for empty state methods to extensions

* Dashboards: Move empty state button hooks to dedicated file

* Dashboards: Render loader while empty state plugin components loading

* Dashboards: Pass empty state default UI as method

* Dashboards: De-duplicate hook usages in empty state

* Dashboards: De-duplicate read-only repo check in empty state

packages/grafana-data/src/types/featureToggles.gen.ts

@@ -1093,6 +1093,11 @@ export interface FeatureToggles {
   */
   enableAppChromeExtensions?: boolean;
   /**
+  * Set this to true to enable all dashboard empty state extensions registered by plugins.
+  * @default false
+  */
+  enableDashboardEmptyExtensions?: boolean;
+  /**
   * Enables use of app platform API for folders
   * @default false
   */

packages/grafana-data/src/types/pluginExtensions.ts

@@ -195,6 +195,7 @@ export enum PluginExtensionPoints {
   AlertingRuleQueryEditor = 'grafana/alerting/alertingrule/queryeditor',
   CommandPalette = 'grafana/commandpalette/action',
   DashboardPanelMenu = 'grafana/dashboard/panel/menu',
+  DashboardEmpty = 'grafana/dashboard/empty',
   DataSourceConfig = 'grafana/datasources/config',
   DataSourceConfigActions = 'grafana/datasources/config/actions',
   DataSourceConfigErrorStatus = 'grafana/datasources/config/error-status',