KCL: Migrate hole to kwargs (#6382)

Previously:

`|> hole(circle(radius = 2, center = p), %)`

Now:

`|> subtract2d(tool = circle(radius = 2, center = p))`

public/kcl-samples/hex-nut/main.kcl

@@ -19,7 +19,7 @@ fn hexNut(start, thk, innerDia) {
     |> angledLine(angle = 60, length = innerDia)
     |> angledLine(angle = 0, length = innerDia * .90)
     |> close()
-    |> hole(circle(center = [start[0], start[1]], radius = innerDia / 2), %)
+    |> subtract2d(tool = circle(center = [start[0], start[1]], radius = innerDia / 2))
     |> extrude(length = thk)
   return hexNutSketch
 }