Revert the use of foundations as rubble placeholders for palisade walls from rP12717 as it just confuses players.
Use the 2x2 stone rubble for now (which is definitely too big but doesn't confuse anyone).
Use it for spikes and the celtic hut too, which had no rubble prior.

Differential Revision: https://code.wildfiregames.com/D691
Split from: D643
Refs #1166
Patch By: temple