LibGfx: Add Rect::translated(dboth)

This corresponds to the current in place Rect::translate_by(dboth).

Userland/Libraries/LibGfx/Rect.h

@@ -168,6 +168,13 @@ public:
         return rect;
     }
 
+    [[nodiscard]] Rect<T> translated(T dboth) const
+    {
+        Rect<T> rect = *this;
+        rect.translate_by(dboth);
+        return rect;
+    }
+
     [[nodiscard]] Rect<T> translated(Point<T> const& delta) const
     {
         Rect<T> rect = *this;