Proposed change

1. I have removed deprecated keys from different language files based on en.yaml as the standard, and added unused keys in English. I also sorted these keys in the same way as en.yaml to facilitate future comparisons.
2. I have written the script used for comparison into nettacker/locale/sync.py for easier future comparisons.

Resolves #1044

Type of change

• New core framework functionality
• Bugfix (non-breaking change which fixes an issue)
• Code refactoring without any functionality changes
• New or existing module/payload change
• Localization improvement
• Dependency upgrade
• Documentation improvement

Checklist

• I've followed the contributing guidelines
• I've run make pre-commit, it didn't generate any changes
• I've run make test, all tests passed locally