Add namespace for module permissions to the module manager

refs #9644

library/Icinga/Application/Modules/Manager.php

@@ -24,6 +24,13 @@ use Icinga\Exception\NotReadableError;
  */
 class Manager
 {
+    /**
+     * Namespace for module permissions
+     *
+     * @var string
+     */
+    const MODULE_PERMISSION_NS = 'module/';
+
     /**
      * Array of all installed module's base directories
      *