Add ERC: Unified Token

[0xZeus1111]

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[eip-review-bot]

✅ All reviewers have approved.

[sennett-lau]

Also suggest to use _ as parameter prefix for function input params: tokenId -> _tokenId, amount -> _amount etc While this could be done after major modifications

[github-actions[bot]]

The commit 4b6f84f27c314918cb3cc40fcce587d36097c6cc (as a parent of dc82165758e24a0c8da29fff8617284eeebf7cc9) contains errors. Please inspect the Run Summary for details.