Create dedicated release page for each Release
What does this MR do?
Implements the dedicated release page for each Release as described in #32827 (closed).
The view shown on this new page is identical to the corresponding release block on the existing Releases page.
What doesn't this MR do?
This MR does not update other areas of the application that should link to this new page instead of the main Releases page. (For example, the Milestones page.) This will be done in a separate MR.
Also, this MR does not update the edit flow. This means that after saving changes to a Release, the user will be redirected back to the main Releases page as they are today. This should probably be changed, but we can tackle this in a separate MR as well.
GIF
Feature flag
This feature is (effectively) hidden behind the release_show_page
feature flag. The Rails route to this page and the link from the Releases page to this page are both hidden behind this flag.