Support more NFT metadata formats

[lukaw3d]

Probably low priority.

• This nft uses cbor encoded metadata:
  https://nexus.oasis.io/v1/sapphire/evm_tokens/oasis1qpwe6h0hw6s0x4skujhznld065300p83wgxnvu0n/nfts/1321

  "metadata_uri": "ipfs://bafyreigxeic7tjivo7ignyjzz7g47kuwctmpjypk42ynwltiu6z3l7rlxm",

  https://gateway.pinata.cloud/ipfs/bafyreigxeic7tjivo7ignyjzz7g47kuwctmpjypk42ynwltiu6z3l7rlxm

• This nft already includes ipfs client in metadata uri:
  https://nexus.oasis.io/v1/sapphire/evm_tokens/oasis1qp5l3994fd7e7ng8ugas8yqqqw7a9x6v85ynq4sh/nfts/195

  "metadata_uri": "https://gateway.pinata.cloud/ipfs/QmbSEsCuAUqF2zK8DViPVFf7CgkEQXbHmHm5Lh93sNfMem/195.json",

Related code:

nexus/analyzer/runtime/evm/erc721.go

Line 103 in e00abe3

rc, err := multiproto.Get(ctx, ipfsClient, metadataURI)

---

https://nexus.oasis.io/v1/sapphire/accounts/0x6D5988C61E1c59C70d3500509C0619257D0647E4/nfts?limit=100&offset=0
https://nexus.oasis.io/v1/sapphire/accounts/0x61f11c7AFB555d8D342a599ee2B73Ed2821C3c1e/nfts?limit=100&offset=0

[lukaw3d]

not sure why this one doesn't have metadata resolved
https://explorer.oasis.io/mainnet/emerald/token/oasis1qpgyvr6vjxz4wamhpwehy7ehghn3m0pqrvxykg8a/instance/15