Add version upgrade for version 4.1 to 4.2

This is necessary for the renamed setting.

Contributes to issue CURA-6311.

plugins/VersionUpgrade/VersionUpgrade41to42/__init__.py

@@ -0,0 +1,54 @@
+# Copyright (c) 2019 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+from typing import Any, Dict, TYPE_CHECKING
+
+from . import VersionUpgrade41to42
+
+if TYPE_CHECKING:
+    from UM.Application import Application
+
+upgrade = VersionUpgrade41to42.VersionUpgrade41to42()
+
+def getMetaData() -> Dict[str, Any]:
+    return {
+        "version_upgrade": {
+            # From                           To                              Upgrade function
+            ("machine_stack", 4000007):      ("machine_stack", 4000008,      upgrade.upgradeStack),
+            ("extruder_train", 4000007):     ("extruder_train", 4000008,     upgrade.upgradeStack),
+            ("definition_changes", 4000007): ("definition_changes", 4000008, upgrade.upgradeInstanceContainer),
+            ("quality_changes", 4000007):    ("quality_changes", 4000008,    upgrade.upgradeInstanceContainer),
+            ("quality", 4000007):            ("quality", 4000008,            upgrade.upgradeInstanceContainer),
+            ("user", 4000007):               ("user", 4000008,               upgrade.upgradeInstanceContainer),
+        },
+        "sources": {
+            "machine_stack": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./machine_instances"}
+            },
+            "extruder_train": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./extruders"}
+            },
+            "definition_changes": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./definition_changes"}
+            },
+            "quality_changes": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./quality_changes"}
+            },
+            "quality": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./quality"}
+            },
+            "user": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./user"}
+            }
+        }
+    }
+
+
+def register(app: "Application") -> Dict[str, Any]:
+    return { "version_upgrade": upgrade }