Eagle: update RTree after moving schematic

After importing, some schmeatics are moved, item at a time.  When moving
schematic items, we need to update the RTree bounding box to allow
searching on position

Fixes #3915 | https://gitlab.com/kicad/code/kicad/issues/3915

eeschema/sch_eagle_plugin.cpp

@@ -815,10 +815,17 @@ void SCH_EAGLE_PLUGIN::loadSheet( wxXmlNode* aSheetNode, int aSheetIndex )
     m_connPoints.clear();
 
     // Translate the items.
-    for( auto item : m_currentSheet->GetScreen()->Items() )
+    std::vector<SCH_ITEM*> allItems;
+
+    std::copy( m_currentSheet->GetScreen()->Items().begin(),
+            m_currentSheet->GetScreen()->Items().end(), std::back_inserter( allItems ) );
+
+    for( auto item : allItems )
     {
         item->SetPosition( item->GetPosition() + translation );
         item->ClearFlags();
+        m_currentSheet->GetScreen()->Update( item );
+
     }
 }