TNL-784: Scroll  to note and open it

**Ticket:** https://openedx.atlassian.net/browse/TNL-784

**Acceptance criteria:**
When the unit is opened from a link from the View All Notes view, the note that was clicked from should be scrolled into view and should be opened for viewing on the unit. To close the note, you can click outside of the note pop-up. Orphaned notes shouldn't have this behavior.

**Sandbox:** http://jmclaus.m.sandbox.edx.org

@polesye @tymofij Please review.
I'd suggest to instantiate `Annotator` here and below.