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/node_decorator.hpp

@@ -12,7 +12,6 @@ struct Box;
 class NodeDecorator : public Node {
  public:
   NodeDecorator(Elements children) : Node(std::move(children)) {}
-  ~NodeDecorator() override {}
   void ComputeRequirement() override;
   void SetBox(Box box) override;
 };