Add locale-aware date formatting for UI dates

[rodrigost23]

Description

Adds locale-aware dates, fixes #470.

Demo

Checklist

• [x] I have read CONTRIBUTING.md in its entirety
• [x] I have performed a self-review of my own code
• [ ] I have added unit tests to cover my changes
• [x] The last commit successfully passed pre-commit checks
• [x] Any AI code was thoroughly reviewed by me