fix(world3D): use the right variable name for creationID

Fixes #36

gamecore/modules/world/world3D.lua

@@ -203,7 +203,7 @@ function World3D:zSortItems(items)
 
     local _, aY, aZ, _, aH, aD = self.bodies:getCube(itemA.mainHitbox)
     aDepth  = itemA.depth
-    aID     = itemA.id
+    aID     = itemA.creationID
     aType   = itemA.type
     aZ     = math.ceil(aZ)
     aY     = math.ceil(aY)
@@ -211,7 +211,7 @@ function World3D:zSortItems(items)
     for _, itemB in ipairs(overlapping) do
       local _, bY, bZ, _, bH, bD = self.bodies:getCube(itemB.mainHitbox)
       bDepth = itemB.depth
-      bID    = itemB.id
+      bID    = itemB.creationID
       bType  = itemB.type
       bZ     = math.ceil(bZ)
       bY     = math.ceil(bY)