feat: specify login UI version on instance and apps (#9071)

# Which Problems Are Solved

To be able to migrate or test the new login UI, admins might want to
(temporarily) switch individual apps.
At a later point admin might want to make sure all applications use the
new login UI.

# How the Problems Are Solved

- Added a feature flag `` on instance level to require all apps to use
the new login and provide an optional base url.
- if the flag is enabled, all (OIDC) applications will automatically use
the v2 login.
  - if disabled, applications can decide based on their configuration
- Added an option on OIDC apps to use the new login UI and an optional
base url.
- Removed the requirement to use `x-zitadel-login-client` to be
redirected to the login V2 and retrieve created authrequest and link
them to SSO sessions.
- Added a new "IAM_LOGIN_CLIENT" role to allow management of users,
sessions, grants and more without `x-zitadel-login-client`.

# Additional Changes

None

# Additional Context

closes https://github.com/zitadel/zitadel/issues/8702

console/src/assets/i18n/id.json

@@ -2255,6 +2255,10 @@
       "CLIENTSECRETREGENERATED": "rahasia klien dihasilkan.",
       "DELETED": "Aplikasi dihapus.",
       "CONFIGCHANGED": "Perubahan terdeteksi!"
+    },
+    "LOGINV2": {
+      "USEV2": "Gunakan UI Login baru",
+      "BASEURL": "URL dasar kustom untuk UI Login baru"
     }
   },
   "GENDERS": { "0": "Tidak dikenal", "1": "Perempuan", "2": "Pria", "3": "Lainnya" },