Add private key copy to clipboard on settings

[damianmarti]

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Are you sure you want to copy your private key to the clipboard?

We can add more information to this message if we want.

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Name	Status	Preview	Comments	Updated (UTC)
burnerwallet-nextjs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 10, 2024 9:47am

[carletex]

Thanks @damianmarti! Merging this!

I think we can have a more friendly UX at some point. And also explaining more about the burner wallet (and what should be used for).

Leaving here some idea from other wallets.

cc @ChangoMan