Close wxDataViewCtrl inline editor when destroying the control.

Close wxDataViewCtrl inline editor when destroying the control.

If the wxDataViewCtrl control was destroyed while an inline editor
control was still active, it wouldn't get destroyed in the right order
and the ~wxWindow assert about unpopped event handlers would be
triggered.

Fix this by popping the handler as one of the first things in
wxDataViewRendererBase destructor.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70002 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775