Update to ipld-prime finally

[liamsi]

After chatting with @Wondertan about this, I think we are finally ready to migrate to ipld-prime.

The main reason is that we are apparently blocked on updating libp2p if we do not also update to ipld-prime. Also, ipfs fully migrated now.

My understanding is that there are two ways to approach this:

1. Do a full migration using only the abstractions of ipld-prime (time consuming but clean; might take 2-3 weeks).
2. Switch to ipld-prime but keep using the old abstractions via adapters (faster but less clean; might take a week roughly)

I'll leave it up to Hlib to decide which route to take here.

Just in case, for 2. these are useful resources:

https://github.com/ipld/go-ipld-prime/blob/master/README_migrationGuide.md
https://github.com/ipld/go-ipld-prime/blob/master/storage/README_adapters.md
https://github.com/ipfs/go-ipld-legacy

I also found this very insightful: ipfs/kubo#7976

supersedes: #6
related: #306

Decision

Do Option 1 above as it is substantially faster to implement and unblocks a few things. So this can be split up into two action items that can be turned into separate issues really:

• Switch to ipld-prime via adapters (testnet)
• Fully migrate to ipld-prime (incentivized testnet)

[Bidon15]

Grooming 16/11/2022:

We decided to not go this path after the Berlin mini-onsite in August.