Inconsistent behavior for PageUp/PageDown key when using the Advanced Inventory Management

[Nhatorama]

When the list on either column spans over more than one page, the PageUp/PageDown keys behave as expected.

When the list is <= 1 page, the PageUp/PageDown expected behavior is inverted (PageUp highlights an item towards the bottom and PageDown highlights an item towards the top of the list).

[epsilon-phase]

@Nhatorama That's from the fact that it wraps around.

I think it's an okay behavior, but perhaps if you aren't already on the top or the bottom, it should move to the top or the bottom.

[Night-Pryanik]

I think that's okay too.