feat: update onboarding network selection buttons

[evavirseda]

Summary

Closes #8532

...

Changelog

- Please write a list of changes

Testing

Platforms

Please select any platforms where your changes have been tested.

• Desktop
  • [ ] MacOS
  • [ ] Linux
  • [ ] Windows

Instructions

Please describe the specific instructions, configurations, and/or test cases necessary to test and verify that your changes work as intended.

...

Checklist

Please tick the following boxes that are relevant to your changes.

• [ ] I have followed the contribution guidelines for this project
• [ ] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have added or modified tests that prove my changes work as intended
• [ ] I have verified that new and existing unit tests pass locally with my changes
• [ ] I have verified that my latest changes pass CI workflows for testing and linting
• [ ] I have made corresponding changes to the documentation