page up/down: move cursor even when view cannot scroll

[KiaraGrouwstra]

currently, when i press pageup or pagedown, my view scrolls unless already at the top/bottom.
in that last cast tho, the cursor is not moved up/down either.
i would find it more intuitive if the cursor might still move to the top/bottom as well.

helix version: 24.3 (2cadec0)