Utilities: Use default constructors/destructors

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/Utilities/find.cpp

@@ -90,7 +90,7 @@ struct FileData {
 
 class Command {
 public:
-    virtual ~Command() { }
+    virtual ~Command() = default;
     virtual bool evaluate(FileData& file_data) const = 0;
 };