BottomBor show/hide logic needs to be improved

show/hide reacts not immediately in case of consuming dy in behavior. User can be in situation when he scrolls list down and the up, but bottom bar is not showing which leads to bad UX.

No file, test, or entry point is named. Start by reproducing the scroll-down-and-up case with the bottom bar, then locate the show/hide behavior and its handling of consumed scroll distance. Done means the bar responds immediately and remains visible when the list returns upward, with a regression test covering the case.

Written by the indexing model from the issue text.