Update ReviewsDiffViewerView to use ReviewRequestViewMixin.

Review Request #9003 — Created June 6, 2017 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
f498059...

Reviewers

This standardizes parts of ReviewsDiffViewerView by using the new
ReviewRequestViewMixin. It centralizes the access checks and review
request fetching, along with improving the documentation, cleaning up
some styling, and adding defaults for member variables.

Tested that the diff viewer still works as expected.