Fix building preview I/O arrows being affected by wires

[EmeraldBlock]

When checking whether a building preview's inputs/outputs are obstructed, buildings in both layers are checked. This means that if there is a wires building next to an input/output, the game wrongly thinks that the input/output is blocked.

This is fixed by only checking the buildings in the same layer as the building preview.

Example of bug

Fixed version

Fixes #648

[Sense101]

is this still not fixed? it looks fine to me from what I can see