dip-1: self-describing hash

[h4x3rotab]

In this DIP, we propose a self-describing hash format to commit arbitrary long data to thereportdata field in a dcap remote attestation report.

Discussion: #330

[amiller]

This reminded me of ipfs multihash format and apparently an RFC 6920:
https://github.com/multiformats/cid
https://discuss.ipfs.tech/t/ipfs-urls-and-rfc-6920/5086

Could be good to explain the differences that motivate a different choice.

• The 64 byte limit is interesting as it means a hex form wouldn't fit.
• it could be worth adding a payload format like multipart data or something for packaging the supporting data along with the rest of the quote for when they need to be sent together