Add failing test for privateToEthAddress

[lukaw3d]

Related to oasisprotocol/explorer@dbdabe6

Apparently none of our existing jest tests touch multiple imports from @ethereumjs/util that check instanceof Uint8Array internally. Otherwise we would have odd failures. Added a skipped test as a reminder

[github-actions]

🦙 MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ EDITORCONFIG	editorconfig-checker	3		0	0.02s
✅ REPOSITORY	checkov	yes		no	16.88s
✅ REPOSITORY	git_diff	yes		no	0.0s
✅ TYPESCRIPT	eslint	3	0	0	4.57s

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[csillag]

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