Bug fix: Play crash whilst loading audio in certain languages

v4 had a critical bug where certain courses would simply stop 'working' when a specific question was loads. This was due to an audio error. We use multiple audio providers to provider you with the best experience, but we cannot anticipate every possible user question. An example, if including characters such as ' or # in questions would cause some voices to break and fail to load. Previously, if an audio had a failure it would crash the entire page. This is now mitigated. You should now see a smaller 'audio error' message but retain the ability to continue learning in this scenario. Audio errors no longer crash the entire page.