DEVAS-1282 Collapse message form on input blur if both title and content input are empty

As I said earlier: While thinking about it and implementing it I saw that if the user clicks on the input to expand then on the content field to fill this one first, then it collapses. So I guess there is a UX problem in the expected result? Or maybe the "when i click somewhere else" means outside the whole blue block. Then instead of the browser onblur event we should implement something more complicated, like handleClickOutside in assembl/static2/js/app/components/debate/navigation/debateLink.jsx or handleTouchOutside in assembl/static2/js/app/components/debate/navigation/timelineSegment.jsx. I'm waiting for instructions as to keep it as is or implement the second solution.