|Expands the cuboid by the given amount in just one direction, and returns the changed cuboid.
If a coordinate is positive, it will expand the high value. If it is negative, it will expand the low value.
Note that you can also specify a single number to expand all coordinates by the same amount (equivalent to specifying a location that is that value on X, Y, and Z).
Inverted by CuboidTag.shrink_one_side
Not valid for multi-member CuboidTags.