Add typing for all version upgrade plug-ins

Hopefully we'll take this typing along when we next copy-paste the stuffs.

Contributes to issue CURA-5936.

plugins/VersionUpgrade/VersionUpgrade33to34/VersionUpgrade33to34.py

@@ -3,17 +3,17 @@
 
 import configparser #To parse preference files.
 import io #To serialise the preference files afterwards.
+from typing import Dict, List, Tuple
 
 from UM.VersionUpgrade import VersionUpgrade #We're inheriting from this.
 
 _renamed_settings = {
     "infill_hollow": "infill_support_enabled"
-}
+} # type: Dict[str, str]
 
 ##  Upgrades configurations from the state they were in at version 3.3 to the
 #   state they should be in at version 3.4.
 class VersionUpgrade33to34(VersionUpgrade):
-
     ##  Gets the version number from a CFG file in Uranium's 3.3 format.
     #
     #   Since the format may change, this is implemented for the 3.3 format only
@@ -25,7 +25,7 @@ class VersionUpgrade33to34(VersionUpgrade):
     #   \raises ValueError The format of the version number in the file is
     #   incorrect.
     #   \raises KeyError The format of the file is incorrect.
-    def getCfgVersion(self, serialised):
+    def getCfgVersion(self, serialised: str) -> int:
         parser = configparser.ConfigParser(interpolation = None)
         parser.read_string(serialised)
         format_version = int(parser.get("general", "version")) #Explicitly give an exception when this fails. That means that the file format is not recognised.
@@ -34,7 +34,7 @@ class VersionUpgrade33to34(VersionUpgrade):
 
     ##  Upgrades instance containers to have the new version
     #   number.
-    def upgradeInstanceContainer(self, serialized, filename):
+    def upgradeInstanceContainer(self, serialized: str, filename: str) -> Tuple[List[str], List[str]]:
         parser = configparser.ConfigParser(interpolation = None)
         parser.read_string(serialized)
 

plugins/VersionUpgrade/VersionUpgrade33to34/__init__.py

@@ -1,11 +1,16 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
+from typing import Any, Dict, TYPE_CHECKING
+
 from . import VersionUpgrade33to34
 
+if TYPE_CHECKING:
+    from UM.Application import Application
+
 upgrade = VersionUpgrade33to34.VersionUpgrade33to34()
 
-def getMetaData():
+def getMetaData() -> Dict[str, Any]:
     return {
         "version_upgrade": {
             # From                           To                              Upgrade function
@@ -35,5 +40,5 @@ def getMetaData():
     }
 
 
-def register(app):
+def register(app: "Application") -> Dict[str, Any]:
     return { "version_upgrade": upgrade }