VisualBuilder: Start working on an interface builder application.

It's tedious making interfaces programmatically. Let's make a program to
help us with this. :^)

Applications/VisualBuilder/VBWidget.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <SharedGraphics/Rect.h>
+
+class VBWidget {
+public:
+    VBWidget();
+    virtual ~VBWidget();
+
+    Rect rect() const { return m_rect; }
+    void set_rect(const Rect& rect) { m_rect = rect; }
+
+private:
+    Rect m_rect;
+};