DynamicOverflow - set overflow on start or end

**Is your feature request related to a problem? Please describe.**

I used the widget `DynamicOverflow`, and it's great but I would really like to have to widget on the left **and** to have the overflow maybe from the start of the list.

There is what I have:


And what I want:


(I want to keep the end of the path and hide the beggining, a little like Windows Explorer. And having the overflow widget on the left).

**Describe the solution you'd like**
Having a parameter like

```
overflowAlignment: MainAxisAlignment.start
```

(It's different from `overflowWidgetAlignment`).