feat: add backup seed

[brancoder]

Summary

resolves #8658
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Changelog

- seed backup for existing profiles and for uploaded stronghold files

Testing

Platforms

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• Desktop
  • MacOS
  • Linux
  • Windows

Instructions

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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
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• I have made corresponding changes to the documentation