Instantiating the LanguageFallbackChain object is somewhat performance intensive.
there are numerous situations (e.g. wikitext page) where we cut short in LinkBeginHookHandler::doOnLinkBegin. In these cases, we shouldn't bother with creating the LanguageFallbackChain here, and only create it when we need.
instead we can inject the LanguageFallbackChainFactory in the class.