Support keyboard navigation with Tab in generic wxDataViewCtrl.

Move keyboard focus between columns with Tab and Shift-Tab. Works
similarly to left and right arrows, but wraps around to go to the next
or previous line and doesn't collapse tree nodes.

If focus reaches the last or first cell, the key event is skipped,
allowing normal Tab handling for moving to another control.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75386 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775