Merge branch 'main' into weilun/speed_dial

# Conflicts:
#	src/slic3r/GUI/Tab.cpp

src/slic3r/GUI/Plater.hpp

@@ -42,6 +42,7 @@ class Button;
 namespace Slic3r {
 
 class BuildVolume;
+class MachineObject;
 enum class BuildVolume_Type : char;
 class Model;
 class ModelObject;