Add a new wxSafeArray<> class wrapping SAFEARRAY.
Also add support for converting VARIANTs containing other, previously
unsupported, standard types.
Closes#14637.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72543 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775