Marker interface for relation type DTOs that are used as response output.
The dedicated Cobra.People360.Api.SeedWork.Converters.RelationTypeOutputConverter resolves the concrete output DTO
deterministically by Cobra.People360.Api.Application.DTOs.IRelationTypeDTO.TypeIdentifier, so a client deserializing
a response always gets the output DTO (incl. runtime-enriched fields such as Firstname).
{
"typeIdentifier": "string",
"isFavorite": true
}