Add warning contexts to not translate XML tags

This went wrong a few times with previous translations. Let's hope that this prevents it from happening again.

Contributes to issue CURA-4113.

cura/Settings/ContainerManager.py

@@ -429,7 +429,7 @@ class ContainerManager(QObject):
         if not Platform.isWindows():
             if os.path.exists(file_url):
                 result = QMessageBox.question(None, catalog.i18nc("@title:window", "File Already Exists"),
-                                              catalog.i18nc("@label", "The file <filename>{0}</filename> already exists. Are you sure you want to overwrite it?").format(file_url))
+                                              catalog.i18nc("@label Don't translate the XML tag <filename>!", "The file <filename>{0}</filename> already exists. Are you sure you want to overwrite it?").format(file_url))
                 if result == QMessageBox.No:
                     return { "status": "cancelled", "message": "User cancelled"}
 

cura/Settings/CuraContainerRegistry.py

@@ -110,7 +110,7 @@ class CuraContainerRegistry(ContainerRegistry):
         if not Platform.isWindows():
             if os.path.exists(file_name):
                 result = QMessageBox.question(None, catalog.i18nc("@title:window", "File Already Exists"),
-                                              catalog.i18nc("@label", "The file <filename>{0}</filename> already exists. Are you sure you want to overwrite it?").format(file_name))
+                                              catalog.i18nc("@label Don't translate the XML tag <filename>!", "The file <filename>{0}</filename> already exists. Are you sure you want to overwrite it?").format(file_name))
                 if result == QMessageBox.No:
                     return
         found_containers = []