@Override
    public String toString() {
        return "ExtendedUiConfig{" +
               "uiConfig=" + uiConfig +
               ", externalIdentityProvider=" + externalIdentityProvider +
               '}';
    }
Allows us to make other back-end config available to the UI while having one mechanism
to cache the config in the ui.
stroom-core-shared/src/main/java/stroom/ui/config/shared/ExtendedUiConfig.java