Search: 1.Select first item in the search list by default

2. Show "Search in English" checkbox only, when Slicer is localized
3. Suppress search window hiding when leave the 3D-scene

src/slic3r/GUI/GUI_App.hpp

@@ -162,6 +162,7 @@ public:
     wxString        current_language_code() const { return m_wxLocale->GetCanonicalName(); }
 	// Translate the language code to a code, for which Prusa Research maintains translations. Defaults to "en_US".
     wxString 		current_language_code_safe() const;
+    bool            is_localized() const { return m_wxLocale->GetLocale() != "English"; }
 
     virtual bool OnExceptionInMainLoop() override;