i18n LMS and Studio components of course handouts

Tagging Kevin Luo from Stanford for the LMS part.

@andy-armstrong can you take a look at the Underscore file? I verified it on localhost.
It only causes a problem if it's displayed and I don't honestly think it is ever displayed - do you see this text when you've not added any handouts? I don't think the data is ever null because there's an `<ol></ol>` by default