[SpeedGrader] Allow document viewing while recording a video comment

[PhillBecker]

Problem statement:

When using the "Media Comment" button and recording a video, we are unable to look at the document we're trying to make comments on. The video window is the only thing active, and the document is frozen and grayed out.

Proposed solution:

Allow the user to view and navigate the graded document and posted comments while recording a media comment video.

User role(s):

instructor