Keyboard navigation seems to not work as expected when compared to a native select. The following 3 problems occur:

Problem A

When scrolling down manually, then hovering over an item, using the keyboard up / down arrows will not cycle through the tems. Instead it will just move the scrollbar.

Steps to reproduce the behavior:

1. Go to Virtualized Select
2. Open the select.
3. Move the scrollbar to roughly 50%.
4. Hover over an item in the last.
5. Use the arrow up or down key.

Expected behavior
When hovering over an item after scrolling down, I expect using the arrow/up keys to cycle through the options rather than just moving the scrollbar.

I expect the behavior to be more in line with https://codesandbox.io/s/q8l6xnvz7w where the scroll bar moves and X item or above or below the previous selected item is selected.

Problem B

Using page down / page up does not change the selected item. Instead it just changes the position of the scrollbar. When using the keyboard up / down arrows you will jump back in the list wherever the focused item was before using page-up / page -down.

Steps to reproduce the behavior:

1. Go to Virtualized Select
2. Open the select
3. Hit page down a couple of times.
4. Use the arrow up or down key.

Expected behavior
When using page-up / page-down the focused item should change, not just the scrollbar.

I expect the behavior to be more in line with https://codesandbox.io/s/q8l6xnvz7w where the scroll bar moves and X item or above or below the previous selected item is selected.

Problem C

When scrolling down manually, then hitting HOME or END, will move the scrollbar but not select the first or last item.

Steps to reproduce the behavior:

1. Go to Virtualized Select
2. Open the select
3. Move the scrollbar to roughly 50%.
4. Hit the HOME or END key.

Expected behavior
The first or last item is not selected, only the scrollbar moves.

I expect the behavior to be more in line with https://codesandbox.io/s/q8l6xnvz7w where both the scroll bar moves and the first / last item is selected.