Utils: Allow BaseTreeView users to hide columns manually

... using a context menu on the header views.

Use the feature in the debugger views where it was previously
un-intuitively available as part of the main context menu of
the view, but not in the header.

Task-number: QTCREATORBUG-24384
Change-Id: I3f030c3dd8ce35dc91bad921e37d2273bfe548b5
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/registerhandler.cpp

@@ -756,7 +756,6 @@ bool RegisterHandler::contextMenuEvent(const ItemViewEvent &ev)
     addFormatAction(tr("Octal"), OctalFormat);
     addFormatAction(tr("Binary"), BinaryFormat);
 
-    Internal::addHideColumnActions(menu, ev.view());
     menu->addAction(action(SettingsDialog)->action());
     menu->popup(ev.globalPos());
     return true;