Implement ERC-4906: EIP-721 Metadata Update Extension

[rsodre]

🧐 Motivation

With the upcoming release of Dojo 1.0, we're expecting a lot of fully on-chain games to be release on Starknet, and with them new ERC-721 and ERC-1155 collections.

Most of those tokens are dynamic, their metadata and image can change from time to time, and currently NFT markets are not able to pick up any updates after mint, we need to manually request a metadata update, one by one.

The first step for Starknet NFT markets to keep tokens updated is to enable them to do so, and that's what ERC-4906 was made for. It specifies the events MetadataUpdate and BatchMetadataUpdate, which can trigger markets to update metadata and token images.

📝 Details

implementation details:
https://eips.ethereum.org/EIPS/eip-4906

There is a cairo implementation from @carbonable-labs, as a component for OZ v0.10.0 here:
https://github.com/carbonable-labs/cairo-erc-4906

ERC-4906 is supported by OpenSea:
https://docs.opensea.io/docs/metadata-standards#metadata-updates