Avoid "KeyError: material_name" crash in Fedora

[hroncok]

Description

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/UM/Qt/ListModel.py", line 54, in data
    return self._items[index.row()][self._role_names[role].decode("utf-8")]
           ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
KeyError: 'material_name'

Downstream report: https://bugzilla.redhat.com/show_bug.cgi?id=2252195
Community: https://community.ultimaker.com/topic/44538-cura-53-crashs-at-startup/

For reasons unknown, this crash does not happen with the AppImage.

Nevertheless, in 2baada8 material_name was added as a role, not material_label. Reaming the field in the sentinel extruder makes the crash go away.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Printer definition file(s)
• Translations

How Has This Been Tested?

On Fedora, I followed the reproducer provided by our users:

1. Expand the settings menu on the upper right side, where the print quality is shown
2. Search for the Build Plate Adhesion setting in Show Custom in the menu and expand it
3. Cura will crash
4. Launch Cura, it crashes on startup

Test Configuration:

• Operating System: Fedora Linux 39

Checklist:

• My code follows the style guidelines of this project as described in UltiMaker Meta and Cura QML best practices
• I have read the Contribution guide
• I have commented my code, particularly in hard-to-understand areas
• I have uploaded any files required to test this change