Add cws availability check.

i18n/en.json

@@ -2575,6 +2575,10 @@
     "id": "api.scheme.patch_scheme.license.error",
     "translation": "Your license does not support update permissions schemes"
   },
+  {
+    "id": "api.server.cws.health_check.app_error",
+    "translation": "CWS Server is not available."
+  },
   {
     "id": "api.server.hosted_signup_unavailable.error",
     "translation": "Portal unavailable for self-hosted signup."