natural rock-> floor/roof, adjusted destruction to match

[PatrikLundell]

Summary

None

Purpose of change

• Change floor/roof from natural rock to actual floor/roof materials.
• Match roof destruction to floor destruction.

Describe the solution

Adjust the JSON definitions to make sense, i.e. use real materials instead of natural rock floor, and match roof destruction to floor destruction.

Describe alternatives you've considered

Testing

• Debug spawn special.
• Teleport to it.
• Inspect that the roof matches the floor (and that materials are reasonable for man-made buildings).
• Do the above for both sites.

Additional context

When the floor is defined as being of the no-roof version, there probably shouldn't be a roof over it...