message: add button label strings
diff: "NAV_SEARCH": "Search",
  "SEARCH_PLACEHOLDER": "Search...",
  "NAV_COMPLAIN": "Complain?",
  + "NAV_DATA_SUBJECT": "Data Subject Contact Form",
  + "DATA_SUBJECT_TITLE": "Data Subject",
  "TITLE_LOGIN": "Login",
  "MANDATORY_EMAIL": "Please provide an email address.",
  "MANDATORY_PASSWORD": "Please provide a password.",
  + "DATA_EXPORT_LABEL": "Export Data",
  + "DELETE_DATA_LABEL": "Delete User Data",
  "LABEL_EMAIL": "Email",
  "LABEL_PASSWORD": "Password",
  "BTN_LOGIN": "Log in",
  