cursor: Update focus at various additional points

cursor: Update focus at various additional points

- When XDG and XWayland views are positioned (view_moved()).
- When unmanaged XWayland surfaces are mapped, unmapped, or moved.

Do not update cursor focus during an out-of-surface drag.

Along with the existing call in desktop_move_to_front(), this
should hopefully cover the majority of cases where the cursor focus
could get out-of-date, with the possible exception of layer-shell
surfaces.