Sales Order Line-Item Reordering

Drag-and-drop reordering is back for sales order line items on orders under 200 lines. For very large orders — over 200 lines — you can now reorder using number inputs, since drag-and-drop doesn't play nicely with the way long lists scroll. We also fixed line items spilling past the edge of the container, which had been causing a sideways scroll and misaligned labels.