COMP: Use default copy, move for construc, assign RealTimeStamp

[jhlegarreta]

Use the compiler-proved default implementations for itk::RealTimeStamp copy constructor, copy assignment, move constructor, and move assignment functions.

As noted in [1], the C++ standard deprecated the implicit generation of copy and assignment operators.

Fixes:

[CTest: warning matched] /Users/builder/externalModules/Core/Common/include/itkRealTimeStamp.h:56:3:
 warning: definition of implicit copy assignment operator for 'RealTimeStamp' is deprecated because it has a user-declared destructor [-Wdeprecated]
  ~RealTimeStamp();
  ^
[CTest: warning matched] /Users/builder/externalModules/Core/Common/include/itkDataObject.h:452:3:
 note: in implicit copy assignment operator for 'itk::RealTimeStamp' first required here
  itkSetMacro(RealTimeStamp, RealTimeStamp);
  ^
[CTest: warning matched] /Users/builder/externalModules/Core/Common/include/itkMacro.h:992:22:
 note: expanded from macro 'itkSetMacro'
      this->m_##name = std::move(_arg);                        \
                     ^
[CTest: warning suppressed] 1 warning generated.

And other similar warnings stemming from itk::RealTimeStamp that have been appearing consistently in some macOS site builds in the dashboard: https://open.cdash.org/viewBuildError.php?type=1&buildid=9579479

[1] https://learn.microsoft.com/bs-latn-ba/cpp/error-messages/compiler-warnings/c5267?view=msvc-150#remarks

PR Checklist

• No API changes were made (or the changes have been approved)
• No major design changes were made (or the changes have been approved)

[jhlegarreta]

@seanm Hopefully this will remove some of the 199 warnings on RogueResearch22.

[dzenanz]

Perhaps the constructor needs to be removed and explicitly or implicitly defaulted?

[N-Dekker]

the C++ standard deprecated the implicit generation of copy and assignment operators.

Just for the sake of completeness, in general, the "rule of zero" is still allowed (even though it assumes implicit generation of copy and assignment operators). But when following the rule of zero, the destructor should also be "implicit".

Thanks Jon, approved 👍