T5455: copy known SSH host fingerprints on image update

[oniko94]

Change summary

On running add system image command, ask a user whether to copy the known SSH host fingerprints (known_hosts file) and copy those to persistent storage on update.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

https://vyos.dev/T5455

Related PR(s)

How to test / Smoketest result

• Build a .deb package of vyos-1x
• Install it to any running VyOS image
• Copy a new ISO image onto the running machine and run add system image vyos-1.x.x.iso
• Reboot into newly installed image
• Make sure the command prompts whether to copy the known hosts
• Make sure the files are copied to the new image
• Make sure they have correct permissions and ownership

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

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No issues in PR Title / Commit Title

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests (no interfaces) ❌ failed
• CLI Smoketests (interfaces only) ❌ failed
• Config tests ❌ failed
• RAID1 tests ❌ failed
• TPM tests ❌ failed