New icons (#2658)

# Description

Updates some icons on the navbar
Closes #()

![image](https://github.com/user-attachments/assets/d88ff4f3-c092-46f9-980a-999e92aeb146)

## Checklist

- [x ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x ] I have performed a self-review of my own code
- [ x] I have attached images of the change if it is UI based
- [ x] I have commented my code, particularly in hard-to-understand
areas
- [ x] If my code has heavily changed functionality I have updated
relevant docs on [Stirling-PDFs doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
- [ x] My changes generate no new warnings
- [ x] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

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Co-authored-by: Reece Browne <reece@stirling.pdf>