Miscellaneous refactoring (#160)

* Reorganize ContainerBase

- Reduce Container overloads using default arguments
- Extract member function pointers to virtual functions
- Separate classes for Vertical, Horizontal and Tab containers

* Collect unpack from NodeDecorator subclasses

* Reduce redundant expansion for aliases

include/ftxui/component/screen_interactive.hpp

@@ -24,7 +24,6 @@ class ScreenInteractive : public Screen {
   static ScreenInteractive FitComponent();
   static ScreenInteractive TerminalOutput();
 
-  ~ScreenInteractive();
   void Loop(Component);
   std::function<void()> ExitLoopClosure();