feat(roles): add subscribe_service permission to Business Admin

This missing permission prevented Business Admin from subscribing to services.

Refs: eclipse-tractusx#172

import/realm-config/generic/catenax-central/CX-Central-realm.json

@@ -433,6 +433,7 @@
                 "view_own_user_account",
                 "view_user_management",
                 "subscribe_apps",
+                "subscribe_service",
                 "view_membership",
                 "update_own_user_account",
                 "request_ssicredential",