Add mouse implementation of most components.

include/ftxui/dom/elements.hpp

@@ -5,6 +5,7 @@
 #include <memory>
 
 #include "ftxui/dom/node.hpp"
+#include "ftxui/screen/box.hpp"
 #include "ftxui/screen/color.hpp"
 #include "ftxui/screen/screen.hpp"
 
@@ -77,6 +78,9 @@ enum Direction { WIDTH, HEIGHT };
 enum Constraint { LESS_THAN, EQUAL, GREATER_THAN };
 Decorator size(Direction, Constraint, int value);
 
+// -- 
+Decorator reflect(Box& box);
+
 // --- Frame ---
 // A frame is a scrollable area. The internal area is potentially larger than
 // the external one. The internal area is scrolled in order to make visible the