Initial version of Metaplex integration

[dchoi27]

Adding acceptance criteria (@yusefnapora):

• Create new API endpoint with header specifying Metaplex auth and validating the signature (JWT) (feat: temp metaplex upload route #740)
• Store public key in our database
• Have NFT.Storage integrated into Metaplex Candy Machine in a side branch feat: add nft.storage upload option metaplex-foundation/metaplex#926
• Test integration

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previous issue:

We want to write a PR to https://github.com/metaplex-foundation/metaplex to integrate with Web3.Storag. @mikeal can you chime in with why you were thinking Web3.Storage would be better? Then we can move this issue over to there.

We've been told this includes making a serverless cloud function that stores data for the Metaplex user and returns what needs to be put into the contract, as well as a PR to Metaplex to offer this as an option.

We'll do some more digging around to see if there's a specific place in their codebase to understand what's needed. @yusefnapora we have a call with them tomorrow morning and will ask and edit this section. Otherwise would be great if you could do some digging and populate this issue with what you find. Moving forward we can also probably pop into their Discord to ask questions: https://discord.gg/bnkV9cRX

Re: the cloud function, we'll just ask them to store using a single user token at this point, and can always expand to adopt new features. We don't think there should be any rate limiting issues if it's a serverless cloud function making the request (since it should be different IP addresses each time). I think Metaplex hosts their own cloud functions, so we can ask to figure out what the path would be to handing it off to them.

We also discussed potentially using the cloud function to index the CID + Solana wallet address for each user. This is publicly available data on the Solana chain, but depending on how easy it is to query it, we might want to do this indexing ourselves (since we won't have any granularity on who stored what data otherwise, given there will be a single Metaplex user at first). I think it's probably fine not to do, but let's discuss (cc @mikeal).

[mikeal]

If we can avoid doing our own additional indexing (on write) for this we should. That was a hypothetical workaround that i hope we don’t need.

There are minor API differences in nft/web3.storage and a few backend differences we hope to be rid of soon. At this point I’ll just let @yusefnapora decide which one is the best fit once he’s in there solving problems 😁

[dchoi27]

Just waiting to push to production

[dchoi27]

@yusefnapora do you think we can close? maybe after tags are added?

[dchoi27]

OK will close this once #948 is added, we make the changes to the Metaplex PR (and let Magic Eden know to include a tag), and then add a PR requiring the tag.

[dchoi27]

Initial version is up, @yusefnapora feel free to make any new issues for work outstanding