Libraries: Use default constructors/destructors in LibGUI

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules

"The compiler is more likely to get the default semantics right and
you cannot implement these functions better than the compiler."

Userland/Libraries/LibGUI/RadioButton.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -24,10 +25,6 @@ RadioButton::RadioButton(String text)
     set_fixed_height(22);
 }
 
-RadioButton::~RadioButton()
-{
-}
-
 Gfx::IntSize RadioButton::circle_size()
 {
     return { 12, 12 };