Revert "Remove "infill mesh" as a standard visible setting"

This reverts commit 46942d7cf23e32dcdf5dbf00440aa781061f4f65.

It was not my decision to make

cura/CuraApplication.py

@@ -253,6 +253,7 @@ class CuraApplication(QtApplication):
             meshfix
             blackmagic
                 print_sequence
+                infill_mesh
             experimental
         """.replace("\n", ";").replace(" ", ""))
 

plugins/3MFReader/ThreeMFReader.py

@@ -71,7 +71,7 @@ class ThreeMFReader(MeshReader):
                 rotation.setByRotationAxis(-0.5 * math.pi, Vector(1, 0, 0))
 
                 # TODO: We currently do not check for normals and simply recalculate them.
-                mesh_builder.calculateNormals()
+                mesh_builder.calculateNormals(flip = True)
                 mesh_builder.setFileName(file_name)
                 node.setMeshData(mesh_builder.build().getTransformed(rotation))
                 node.setSelectable(True)

plugins/PerObjectSettingsTool/PerObjectSettingsTool.py

@@ -77,7 +77,10 @@ class PerObjectSettingsTool(Tool):
             if not self._multi_extrusion:
                 default_stack_id = global_container_stack.getId()
             else:
-                default_stack_id = ExtruderManager.getInstance().getExtruderStack(0).getId()
+                default_stack = ExtruderManager.getInstance().getExtruderStack(0)
+                if default_stack:
+                    default_stack_id = default_stack.getId()
+                else: default_stack_id = global_container_stack.getId()
 
             root_node = Application.getInstance().getController().getScene().getRoot()
             for node in DepthFirstIterator(root_node):

plugins/SolidView/SolidView.py

@@ -51,6 +51,8 @@ class SolidView(View):
             if multi_extrusion:
                 support_extruder_nr = global_container_stack.getProperty("support_extruder_nr", "value")
                 support_angle_stack = ExtruderManager.getInstance().getExtruderStack(support_extruder_nr)
+                if not support_angle_stack:
+                    support_angle_stack = global_container_stack
             else:
                 support_angle_stack = global_container_stack