ServiceAccount: Update service account api resource and add service account token (#92972)

* Create own legacy store function to list service accounts and update api model

* Add service account tokens as a sub resource for service accounts

pkg/registry/apis/iam/legacy/testdata/mysql--users_query-users_uid.sql

@@ -2,7 +2,7 @@ SELECT o.org_id, u.id, u.uid, u.login, u.email, u.name,
   u.created, u.updated, u.is_service_account, u.is_disabled, u.is_admin
   FROM `grafana`.`user` as u JOIN `grafana`.`org_user` as o ON u.id = o.user_id
  WHERE o.org_id = 0
-   AND u.is_service_account = FALSE
+   AND NOT u.is_service_account
    AND u.uid = 'abc'
  ORDER BY u.id asc
  LIMIT 1