remove ui namespace which is not really used, move CameraData in camera_modes.h to avoid the inclusion of canva.h

src/node_dialog_layer_rename.cpp

@@ -36,7 +36,7 @@ void NodeDialogLayerRename::init_controls()
 
 void NodeDialogLayerRename::loaded()
 {
-//    ui::Image thumb = ui::Canvas::I->thumbnail_read(data_path);
+//    Image thumb = Canvas::I->thumbnail_read(data_path);
 //    auto image_tex = find<NodeImageTexture>("thumb-tex");
 //    image_tex->tex.create(thumb);
 }