TNL-932: Add styling to Notes page.

TNL-932
@tymofij, @jmclaus, @clrux please review.

**sandbox:** http://tymofij.m.sandbox.edx.org/courses/edX/DemoX/Demo_Course/edxnotes/
> what is this used for? do we really need it?

It returns recently viewed component. See https://github.com/edx/edx-platform/blob/anton/edxnotes-apply-ui/lms/templates/edxnotes/edxnotes.html#L57