我有以下项目集合:[{"_id":1,"manufactureId":1,"itemTypeId":"Type1"},{"_id":2,"manufactureId":1,"itemTypeId":"Type2"},{"_id":3,"manufactureId":2,"itemTypeId":"Type1"}]我想创建一个查询，该查询将返回每个制造商在以下结构(或类似结构)中具有的每种商品类型的商品数量:[{_id:1,//thiswouldbethemanufactureIditemsCount:{"Type1":1,//Type1itemscount"Type2":1//...}