Set encoding to utf-8 when writing files

Since we assume utf-8 in a lot of places.

Contributes to CURA-2692

plugins/RemovableDriveOutputDevice/RemovableDriveOutputDevice.py

@@ -67,7 +67,7 @@ class RemovableDriveOutputDevice(OutputDevice):
         try:
             Logger.log("d", "Writing to %s", file_name)
             # Using buffering greatly reduces the write time for many lines of gcode
-            self._stream = open(file_name, "wt", buffering = 1)
+            self._stream = open(file_name, "wt", buffering = 1, encoding = "utf-8")
             job = WriteMeshJob(writer, self._stream, node, MeshWriter.OutputMode.TextMode)
             job.setFileName(file_name)
             job.progress.connect(self._onProgress)

plugins/VersionUpgrade/VersionUpgrade21to22/MachineInstance.py

@@ -111,7 +111,7 @@ class MachineInstance:
         user_profile_file = os.path.join(user_storage, urllib.parse.quote_plus(self._name) + "_current_settings.inst.cfg")
         if not os.path.exists(user_storage):
             os.makedirs(user_storage)
-        with open(user_profile_file, "w") as file_handle:
+        with open(user_profile_file, "w", encoding = "utf-8") as file_handle:
             user_profile.write(file_handle)
         version_upgrade_manager.upgradeExtraFile(user_storage, urllib.parse.quote_plus(self._name), "user")