Improve variable declaration in some model definitions

[theEvilReaper]

Proposed changes

With the merge of pull request #20, several variables have been renamed to improve handling across different scenarios. In our case, this makes the Flutter project for Stelaris more readable and improves the clarity of variable usage.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• I have read the CONTRIBUTING.md
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)