Search: Fix empty folder details for nested folder items (#76504)

* Introduce dashboard.folder_uid column

* Add data migration

* Search: Fix empty folder details for nested folders

* Set `dashboard.folder_uid` and update tests

* Add unique index

* lint

Ignore cyclomatic complexity of func
`(*DashboardServiceImpl).BuildSaveDashboardCommand

* Fix search by folder UID

pkg/services/sqlstore/permissions/dashboard_test.go

@@ -815,8 +815,9 @@ func setupNestedTest(t *testing.T, usr *user.SignedInUser, perms []accesscontrol
 
 	// create dashboard under parent folder
 	_, err = dashStore.SaveDashboard(context.Background(), dashboards.SaveDashboardCommand{
-		OrgID:    orgID,
-		FolderID: parent.ID,
+		OrgID:     orgID,
+		FolderID:  parent.ID,
+		FolderUID: parent.UID,
 		Dashboard: simplejson.NewFromAny(map[string]any{
 			"title": "dashboard under parent folder",
 		}),
@@ -825,8 +826,9 @@ func setupNestedTest(t *testing.T, usr *user.SignedInUser, perms []accesscontrol
 
 	// create dashboard under subfolder
 	_, err = dashStore.SaveDashboard(context.Background(), dashboards.SaveDashboardCommand{
-		OrgID:    orgID,
-		FolderID: subfolder.ID,
+		OrgID:     orgID,
+		FolderID:  subfolder.ID,
+		FolderUID: subfolder.UID,
 		Dashboard: simplejson.NewFromAny(map[string]any{
 			"title": "dashboard under subfolder",
 		}),