[LazyTree]: add auto-scrolling after expanding last item

## Now

1. Open any lazy tree datasource (picker or table view) https://uui.epam.com/documents?id=pickerInput&mode=doc&skin=UUI4_promo&category=components
2. Open South America and scroll down to the last element
3. Click last element to expand child items

https://user-images.githubusercontent.com/37875890/208648627-03cdd131-7d1e-4d50-bfc3-225db7eae024.mp4

## Describe the solution you'd like (optional)

Currently only icon and scoll-thumb are updated. This behavior isn't obvious for some users. Would it be better to add scroll down in order to make visible expanded child items.

Reproduce the behavior in the LazyTree datasource using the picker or table view from the linked UUI documentation: expand the last visible item after scrolling to the bottom. Start by locating the LazyTree expansion and scroll handling, then verify that expanding the final item makes its child items visible in both examples.

Written by the indexing model from the issue text.