Valera/carry over of add option transcripts remove onhover 2

<b>Description</b>
This is a copy of the PR https://github.com/edx/edx-platform/pull/1183 . All of the commits from https://github.com/edx/edx-platform/pull/1183 have been cherry-picked into this PR.

<b>Reviewers</b>
- @brianhw 
- @Lyla-Fischer