MiniProjectTargetSelector: Ensure selected item is visible on show event

Is useful when project contains large amount of targets and you have
to switch between them more or less often. Change also applies to other
tree views in selector but they are less likely to contain large
row counts.

Change-Id: Ic2cd920335adeef618d85202b3347a4cd042871c
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/miniprojecttargetselector.cpp

@@ -389,6 +389,12 @@ private:
         TreeView::mouseReleaseEvent(event);
     }
 
+    void showEvent(QShowEvent* event) override
+    {
+        scrollTo(currentIndex());
+        TreeView::showEvent(event);
+    }
+
     QObject *objectAt(const QModelIndex &index) const
     {
         return theModel()->itemForIndex(index)->object();