dwindle: move to CBox for expressing nodes

src/helpers/Box.cpp

@@ -101,4 +101,12 @@ CBox CBox::roundInternal() {
     float newH = y + h - std::floor(y);
 
     return CBox{std::floor(x), std::floor(y), std::floor(newW), std::floor(newH)};
-}
+}
+
+Vector2D CBox::pos() const {
+    return {x, y};
+}
+
+Vector2D CBox::size() const {
+    return {w, h};
+}