ERC-6909 Minimal Multi-Token Interface

FinalERCcreated 2023-04-192 later proposals build on itrequires ERC-165

A minimal specification for managing multiple tokens by their id in a single contract.

Authors: JT Riley (@jtriley2p), Dillon (@d1ll0n), Sara (@snreynolds), Vectorized (@Vectorized), Neodaoist (@neodaoist)

Functions this standard introduces (5)

`0x426a8493`	`approve(address,uint256,uint256)`
`0x558a7297`	`setOperator(address,bool)`
`0x01ffc9a7`	`supportsInterface(bytes4)`	pure
`0x095bcdb6`	`transfer(address,uint256,uint256)`
`0xfe99049a`	`transferFrom(address,address,uint256,uint256)`

Topic0 is the keccak256 hash of the signature, which is what a log filter matches on.

`0x1b3d7edb2e9c0b0e7c525b20aaaef0f5940d2ed71663c7d39266ecafac728859`	`Transfer(address,address,address,uint256,uint256)`
`0xceb576d9f15e4e200fdb5096d64d5dfd667e16def20c1eefd14256d8e3faa267`	`OperatorSet(address,address,bool)`
`0xb3fd5071835887567a0671151121894ddccc2842f1d10bedad13e0d17cace9a7`	`Approval(address,address,uint256,uint256)`

`0xf6deaa04`	`InsufficientBalance(address,uint256)`
`0x731555bd`	`InsufficientPermission(address,uint256)`

Proposals this one names in its requires field.

Later proposals that name this one in their requires field.