(1) To fire a new keyvalue struct, three parameters should be
    provided in the following manner:
        DispatchKeyValue(entity, "KeyName", "Value");
    The "szClassName" value will automatically use the classname
    of the specified entity, "fHandled" will be set to 0.
(2) Inside the pfn_keyvalue() forward this native can be used to
    modify the keyvalue struct inline, two parameters should be
    provided in the following manner:
       DispatchKeyValue("KeyName", "Value");
    The "szClassName" or "fHandled" values can not be changed.