Desktop: OneNote importer: Simplify reporting import issues to the forum

[personalizedrefrigerator]

Summary

This change simplifies reporting OneNote import issues. Previously, no feedback was shown when the importer failed to process a OneNote file. With this change, the "Please consider sending a bug report to the forum" dialog is also shown for OneNote imports.

Testing plan

On MacOS 26.0.1:

1. Download OneWithFileData.one (a .one file in an unsupported format).
2. Create a new .zip file containing OneWithFileData.one.
3. Import the .zip file using Joplin's File > Import > "ZIP - OneNote notebook".
4. Verify that the import failure dialog is shown.
5. Click "Send bug report".
6. Verify that the "Send bug report" button links to the Joplin forum, with a pre-filled support request template.
7. Dismiss the "Send bug report" dialog.
8. Import the corrupted_attachment.zip test OneNote file.
9. Verify that the import process completes successfully (without showing the "Send bug report" dialog).