Fix reentrancy in wxDataViewRendererBase::FinishEditing().

Fix reentrancy in wxDataViewRendererBase::FinishEditing().

Switching focus to the main wxDataViewCtrl window resulted in focus loss event
and a reentrant call to FinishEditing() itself if it wasn't called because the
in-place edit control was being destroyed the first time.

Fix this by destroying the in-place control first and adjusting the focus
later, the effect should be exactly the same but now FinishEditing() can be
safely called from anywhere in the code.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69896 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775