An OAuth client: from a Client ID Metadata Document, dynamically registered, or registered by the host.
@type t() :: %Sake.Auth.Client{ application_type: term(), client_uri: term(), grant_types: term(), id: term(), kind: term(), logo_uri: term(), name: term(), redirect_uris: term(), scopes: term(), secret_hash: term(), token_endpoint_auth_method: term() }