* Fix construction ghost shader name
Construction ghosts were using a shader called `selection_outline_unshader`, which is not a valid shader name. This caused a crash when constructing things. This fixes that problem by updating them to use a valid shader `unshaded`.
I haven't followed the changes to shaders, but it's likely that this was caused by the shader name being changed and not updated in the construction ghost prototype.
* Remove specific outline shader for construction ghost prototypes
No longer needed.
4e2f694a0d