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/component/button.cpp

@@ -23,8 +23,6 @@ class ButtonBase : public ComponentBase {
              Ref<ButtonOption> option)
       : label_(label), on_click_(on_click), option_(std::move(option)) {}
 
-  ~ButtonBase() override = default;
-
   // Component implementation:
   Element Render() override {
     auto style = Focused() ? inverted : nothing;

src/ftxui/component/catch_event.cpp

@@ -13,7 +13,6 @@ class CatchEventBase : public ComponentBase {
   // Constructor.
   CatchEventBase(std::function<bool(Event)> on_event)
       : on_event_(std::move(on_event)) {}
-  ~CatchEventBase() override = default;
 
   // Component implementation.
   bool OnEvent(Event event) override {

src/ftxui/component/checkbox.cpp

@@ -29,8 +29,6 @@ class CheckboxBase : public ComponentBase {
 #endif
   }
 
-  ~CheckboxBase() override = default;
-
  private:
   // Component implementation.
   Element Render() override {

src/ftxui/component/component.cpp

@@ -14,10 +14,7 @@
 namespace ftxui {
 
 namespace {
-class CaptureMouseImpl : public CapturedMouseInterface {
- public:
-  ~CaptureMouseImpl() override {}
-};
+class CaptureMouseImpl : public CapturedMouseInterface {};
 }  // namespace
 
 ComponentBase::~ComponentBase() {
@@ -161,9 +158,9 @@ void ComponentBase::TakeFocus() {
 /// @param event
 /// @ingroup component
 CapturedMouse ComponentBase::CaptureMouse(const Event& event) {
-  if (!event.screen_)
-    return std::make_unique<CaptureMouseImpl>();
-  return event.screen_->CaptureMouse();
+  if (event.screen_)
+    return event.screen_->CaptureMouse();
+  return std::make_unique<CaptureMouseImpl>();
 }
 
 }  // namespace ftxui

src/ftxui/component/container.cpp

@@ -53,8 +53,6 @@ class ContainerBase : public ComponentBase {
     return container;
   }
 
-  ~ContainerBase() override = default;
-
   // Component override.
   bool OnEvent(Event event) override {
     if (event.is_mouse())

src/ftxui/component/input.cpp

@@ -24,7 +24,6 @@ class InputBase : public ComponentBase {
             ConstStringRef placeholder,
             Ref<InputOption> option)
       : content_(content), placeholder_(placeholder), option_(option) {}
-  ~InputBase() override = default;
 
   int& cursor_position() { return *(option_->cursor_position); }
 

src/ftxui/component/radiobox.cpp

@@ -38,7 +38,6 @@ class RadioboxBase : public ComponentBase {
       option_->style_unchecked = L"( )";
 #endif
   }
-  ~RadioboxBase() override = default;
 
  private:
   Element Render() override {

src/ftxui/component/renderer.cpp

@@ -18,7 +18,6 @@ class RendererBase : public ComponentBase {
 
   // Constructor.
   RendererBase(std::function<Element()> render) : render_(std::move(render)) {}
-  ~RendererBase() override = default;
 
   // Component implementation.
   Element Render() override { return render_(); }

src/ftxui/component/toggle.cpp

@@ -29,8 +29,6 @@ class ToggleBase : public ComponentBase {
              Ref<ToggleOption> option)
       : entries_(entries), selected_(selected), option_(std::move(option)) {}
 
-  ~ToggleBase() override = default;
-
  private:
   Element Render() override {
     Elements children;