Add trait: Fork Protection

[jceb]

In the presentation of did:webplus on 13 Jan (https://github.com/decentralized-identity/identifiers-discovery/blob/main/agenda.md#meeting---13-jan-2025---1400-et--recording) a potentially interesting new trait was presented: Fork Protection of DID documents. The idea is to have mechanisms in place that prevent forks of DID documents, i.e. multiple versions of the DID document exist at the same time and are presented to different entities requesting the document (presumably with the intention of committing fraud). KERIs witnesses provide protection against such behavior, another mechanism was presented for did:webplus.

[ankurdotb]

It depends on whether the DID is controlled by the original author. Publishing a DIDDoc to multiple methods could be a feature, not a bug, that a DID publisher opts in to. E.g., publishing a did:webvh and a "also known as" DID on did:iden3, did:cheqd etc for compatibility reasons.

Someone external coming and just copying it without the original author's permission is where the issue lies. Is it this latter case we're talking about?