Versions
WorldEdit version: 7.2.0 beta 4
Platform version: 1.16.2 Fabric/Forge

Describe the bug
The MC box excludes the max point, so we need to add one when converting to it for optimized entity selection.

To Reproduce

1. Try to copy entities in a one-block region
2. Notice they are excluded for some reason.

Expected behavior
Entities can be copied properly.

Additional context
Split from #1520.