Windowview: Fix broken keyboard navigation while filtering

After the 5.25 update, one could not see which window was highlighted until one manually unfocused the SearchField and then pressed any key to refresh the WindowHeap. Also, the searchbar would (most of the time) "absorb" the arrow keys so one had to also unfocus it to really be able to select windows with they keyboard.

With this change, there is always one window highlighted while filtering using the search box. Also, one can select another window with the arrow keys without manually unfocusing the searchbox. This heavily improves the keyboard functionality in this effect that got lost with the 5.25 update of presentwindows to windowview and resolves complaints about the keyboard navigation being buggy.

BUG: 455633 BUG: 455764 BUG: 455099 BUG: 455586 BUG: 455753 FIXED-IN: 5.25.2