Add the possibility to disable invisible wxDataViewCtrl items.

Add new wxDataViewModel::IsEnabled() and wxDataViewListStore::IsEnabledByRow()
methods and implement support for actually disabling the items in wxOSX/Cocoa
native implementation of wxDataViewCtrl and limited support for it in the
generic version.

We need to implement this in wxGTK using GtkCellRenderer "sensitive" propriety
later.

Closes #12686.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66403 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/datavcmn.cpp

@@ -790,6 +790,8 @@ void wxDataViewRendererBase::PrepareForItem(const wxDataViewModel *model,
     wxDataViewItemAttr attr;
     model->GetAttr(item, column, attr);
     SetAttr(attr);
+
+    SetEnabled(model->IsEnabled(item, column));
 }