Include border widths when measuring grid templates for controls (#6622)

**Problem:**

Border width is not taken into account when calculating grid template
measurements, which results in the grid placeholders being misplaced.

**Fix:**

Include the border widths in the special size measurements and use them
(transparent) for the grid placeholder styles.

Fixes #6619

Author: ruggi

editor/src/components/canvas/__snapshots__/ui-jsx-canvas-bugs.spec.tsx.snap

@@ -162,6 +162,12 @@ Object {
       "alignItems": null,
       "alignSelf": null,
       "borderRadius": null,
+      "borderWidths": Object {
+        "bottom": 0,
+        "left": 0,
+        "right": 0,
+        "top": 0,
+      },
       "clientHeight": 0,
       "clientWidth": 0,
       "closestOffsetParentPath": Object {
@@ -328,6 +334,12 @@ Object {
       "alignItems": null,
       "alignSelf": null,
       "borderRadius": null,
+      "borderWidths": Object {
+        "bottom": 0,
+        "left": 0,
+        "right": 0,
+        "top": 0,
+      },
       "clientHeight": 0,
       "clientWidth": 0,
       "closestOffsetParentPath": Object {