feat(authz): Dummy ers that just returns claims

[elizabethhealy]

resolves https://github.com/opentdf/platform/issues/788 resolves https://github.com/opentdf/platform/issues/785

Simple entity resolution service that just looks at claims

CreateEntityChainFromJwt will return an entity of type claims with the claims being the contents of the jwt ResolveEntities returns the entity representation if not type claims, and if type claims then it just returns the claims

Mode in the config to dictate which ERS to run -- default is keycloak