Don't mix up column internal indices and display positions in wxGrid keyboard navigation code. This ensures that pressing left/right cursor arrows always moves the cursor to the previous/next column on the display, even if the columns were reordered. Closes #13281. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67944 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775