feat(authmethods): Add typed attributes to authenticate request and response

The AuthenticateRequest and AuthenticateResponse types have a
complex mapping rule system, which requires a pair of custom
callback functions.

internal/proto/controller/api/resources/authtokens/v1/authtoken.proto

@@ -42,9 +42,6 @@ message AuthToken {
 	// Output only. The time this Auth Token expires.
 	google.protobuf.Timestamp expiration_time = 110 [json_name="expiration_time"];
 
-	// Output only. The type of this auth token. Either "cookie" or "token".
-	string token_type = 120 [json_name="token_type"];
-
 	// Output only. The available actions on this resource for this user.
 	repeated string authorized_actions = 300 [json_name="authorized_actions"];
 }