explicit roofs on canteen 1

[PatrikLundell]

Summary

None

Purpose of change

Add explicit roofs to expansion canteen 1, as well as chimneys/stove pipes on said roof.

Describe the solution

Use the 3D syntax to update the JSON files.

Describe alternatives you've considered

• Change the metal material from junk to scrap metal (like most other cases use).

Testing

• Created the whole construction of the expansion in 7 different materials, plus fireplaces and smoking racks.
• Verified that the results looked correct.
• Created the first section of it from the first material and added stoves.
• Verified that those two pieces looked correct as well.

Additional context

• Pruned the palette usages to only use the common one when elements from it were used.
• Fixed an error report bug so I could see what I'd screwed up and fix that.