Remove explicit default destructors (#157)

From CppCoreGuidelines:

Rule of Zero: C.20: If you can avoid defining default operations, do.
C.52: Use inheriting constructors to import constructors into a derived class that does not need further explicit initialization.
DRY forward and using declarations.
Miscellaneous:

Fix format.sh to output examples with normalised paths in sorted order.

Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

src/ftxui/dom/color.cpp

@@ -30,7 +30,6 @@ class FgColor : public NodeDecorator {
  public:
   FgColor(Elements children, Color color)
       : NodeDecorator(std::move(children)), color_(color) {}
-  ~FgColor() override {}
 
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {