Reproduction link

https://stackblitz.com/edit/ng-zorro-antd-ivy-d3beif?file=src%2Fapp%2Fapp.component.ts,src%2Fapp%2Fapp.module.ts

Steps to reproduce

/

What is expected?

nz-tree-view can use NestedTreeControl

What is actually happening?

https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/components/tree-view/node.ts#L75
tree-view-node use treeControl.isExpandable() but the function is only for flat tree node