ENH: optimize object list

1. remove min size logic
2. remove some not used code
3. fix the current item not visible issue after size change

Change-Id: Ibf39cc4f9e330faadb5d552e7b8a94c0b601513b
Signed-off-by: yifan.wu <yifan.wu@bambulab.com>

src/slic3r/GUI/GUI_ObjectList.hpp

@@ -450,11 +450,6 @@ private:
 	void OnEditingStarted(wxDataViewEvent &event);
     void OnEditingDone(wxDataViewEvent &event);
 
-    // BBS
-    void OnColumnHeadClicked(wxDataViewEvent& event);
-    void OnOrganizeObjects(OBJECT_ORGANIZE_TYPE type);
-    wxMenu m_object_org_menu;
-
     std::vector<int> m_columns_width;
 };