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/clear_under.cpp

@@ -13,8 +13,7 @@ using ftxui::Screen;
 
 class ClearUnder : public NodeDecorator {
  public:
-  ClearUnder(Elements children) : NodeDecorator(std::move(children)) {}
-  ~ClearUnder() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {