Modify ETH keys to support pallet-revive

[aramikm]

Goal

The goal of this PR is to modify accounts to be compatible with ETH keys used inn pallet-revive.

Closes #2289

Discussion

• This is not a backwards compatible change but it doesn't appear that we have any accounts with previous formatting so it should be safe.

Checklist

• Unit Tests added?
• e2e modified
• Spec version incremented?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
common/primitives/src/signatures.rs	72.40% <100.00%> (+13.46%)	⬆️
pallets/passkey/src/tests_v2.rs	100.00% <100.00%> (ø)

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[wilwade]

Looks good to me

• Reviewed code
• Reviewed Pallet Revive to confirm eeeeeeeeeeeeeeeeeeeeeeee

[JoeCap08055]

Some comment/doc nits, but non-blocking. Approved.