[vtadmin] Rehome DangerAction component in a common folder

[doeg]

Description

A tiny little refactor (prefactor?!) as a precursor to #8732, since I'm going to be using that DangerAction component on the Shard page. Also added a couple of missing copyrights.

Related Issue(s)

Prefactor for #8732

Checklist

• "Backport me!" label has been added if this change should be backported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

N/A

[github-actions]

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