Adding automatic scrolling on item focus for non-virtualized collections (#2232)
* moving useSelectableList scrolling code to useSelectableCollection
allows non virtualized tables/grids created with useTable/useGrid to have automatic scrolling when moving focus via arrow keys
* adding stories and fixing useSelectableCollection scroll behavior
some components will have a ref that is not the same element as the scrollable region so add a prop for scrollRef
* fixing lint
* fixing lint
* addressing review comments
* fixing lint and removing isVirtualized from tablist props