fix(admin): repair email rollback and product taxonomy APIs

Call the existing Email_Rollback::list_pending method instead of the missing
list_recent_changes method that caused /email-rollback/users to fatal. Add
the product taxonomy route expected by ProductEditorDrawer and return
category/tag options for the editor.

inc/classes/admin/class-aksrt-admin-tools-controller.php

@@ -261,7 +261,7 @@ class AKSRT_Admin_Tools_Controller extends AKSRT_Admin_Controller_Base {
 
         $page = max(1, (int) $request->get_param('page'));
         $per_page = min(100, max(1, (int) $request->get_param('per_page')));
-        $data = AKSRT_Email_Rollback::list_recent_changes($page, $per_page);
+        $data = AKSRT_Email_Rollback::list_pending($page, $per_page);
 
         return $this->success(['data' => $data]);
     }