Add debugger visualizers for Visual Studio 2012+.

Starting with 2012, Visual Studio uses a new, XML-based and actually
quite understandable format for the debug visualizers. Only basics are
included so far.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75102 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775