A regression in one of the later RCs broke displaying the draft banner

after editing an existing published review request. The placeholder

banner in the DOM was being set prematurely as the active banner, and

never shown.
We now only add the banner up-front if it's visible, and we make sure to

show it when needed.

Tested editing a review request without a draft banner.
Tested loading review requests with drafts, and ones that were closed

(both discarded and submitted).
Unit tests pass.