Parses an XML node expectedly created via createFormattedMessageXML, and localizes it into a user presentable message using the specified ResourceLoader
Generally in Sakai, i18n happens at the moment when the user is accessing content - we invoke ResourceLoaders to get formatted messages using the locale that is appropriate to the user.
Convenience method:
If the Exception is an instance of ContentReviewProviderException, the item's lastError is set to the exception's I18nXml;
otherwise it falls back to getLocalizedMessage()
If the Exception is an instance of ContentReviewProviderException, the item's lastError is set to the exception's I18nXml;
otherwise it falls back to leu;
if leu is null, it falls back to getLocalizedMessage()