We've previously been generating the human-readable information on the

review request's status (created time, updated time) in the review

request box template. This was a bit messy, and covered up issues like

the created timestamp never showing up when there's a draft.
This logic has been moved server-side to a reusable function that allows

additional information (like the diffset information in the diff viewer)

to be tacked on. Other views could potentially add their own information

as well. This handles creating a consistent representation for each of

the bits of status, reducing the complexity and improving the

performance of the template in the process.
Since this is more consolidated, it also allows for new unit tests that

ensure the correct output.

Unit tests pass.
Tested various states manually in the review request page and the diff

viewer.