Function groupParticipantFromRegistry

groupParticipantFromRegistry(
    registry: Registry,
    owner: OwnerRecord,
    document: XIDDocument,
): GroupParticipant
Create a GroupParticipant from a XIDDocument, validating against the registry.

Port of group_participant_from_registry() from cmd/dkg/common.rs lines 133-149.
Parameters
- registry: Registry
- owner: OwnerRecord
- document: XIDDocument
Returns GroupParticipant
- Defined in cmd/dkg/common.ts:187