Fix spurious label editing in generic wx{List,Tree,DataView}Ctrl.

Fix spurious label editing in generic wx{List,Tree,DataView}Ctrl.

Clicking on the control to give it focus must not start editing the label of
an item in it, this is bad UI as you need to carefully select where do you
click to avoid starting to edit the label and nobody else does it like this
(probably because of the former reason).

As a side note, it would be really great to abstract the item handling in a
class that could be reused by all these controls instead of having to update 3
slightly different versions of the same code every time.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775