make oauth endpoints openid compliant

database/migrations/structure/20230411_1736_oauth_openid.sql

@@ -0,0 +1,4 @@
+ALTER TABLE `oauth_tokens`
+ADD `scope` varchar(255) NOT NULL DEFAULT '',
+ADD `access_token` varchar(255) CHARACTER SET ascii COLLATE ascii_bin DEFAULT NULL,
+ADD UNIQUE `access_token` (`access_token`);