move abr import to main menu, add progress bar

src/node_panel_brush.h

@@ -28,7 +28,6 @@ class NodePanelBrush : public Node
     // brushes that are marked as deleted but file still exists
     std::vector<std::string> m_deleted;
     NodeButtonBrush* m_current = nullptr;
-    NodeScroll* m_container;
     NodeButtonCustom* m_btn_add;
     NodeButtonCustom* m_btn_up;
     NodeButtonCustom* m_btn_down;
@@ -47,6 +46,7 @@ class NodePanelBrush : public Node
         bool m_user_brush = false;
     };
 public:
+    NodeScroll* m_container;
     std::string m_dir_name;
     std::function<void(Node* target, int index)> on_brush_changed;
     std::function<void(Node* target)> on_popup_close;