脚本触发器
has_unlocked_heir_selection_trigger
检查内容
拥有变量：
unlocked_heir_selection_$type$调用它的脚本会填入这些值，各调用处见“关联”。
$type$
custom_description = {
text = has_unlocked_heir_selection_trigger_text
value = heir_selection:$type$
has_variable = unlocked_heir_selection_$type$
}