✨ New `PositiveInteger.unaryMinus()` function

[LVMVRQUXL]

📝 Description

We want to add the PositiveInteger.unaryMinus() experimental function for returning the negative of this integer. This function should be available for all Kotlin platforms and Java.

operator fun PositiveInteger.unaryMinus(): NegativeInteger = TODO()

🔗 Dependencies

This issue is blocked by the following items:

• [ ] #661
• [ ] #821

✅ Checklist

See the Issue implementation section in the contributing guidelines before addressing the following checklist.

• [ ] ✨ Add the function with tests, documentation and samples.
• [ ] 📝 Update the unreleased changelog for this issue.
• [ ] 📝 After closing this issue, update the status of tracking issues depending only on this one.