Fix Finished Announcement banner results link

[shaunanoordin]

PR Overview

Package: app-project Fixes #6370

This PR fixes the Finished Announcement banner's "See Results" link.

• Prior to this fix, the "See Results" link failed to add a "/projects" to the URL.
• Storybook Story has been fixed: 'baseUrl' now matches the 'baseUrl' returned by the Project store (which doesn't automagically prepend a "/projects" to the project slug).
• Tests have been fixed: prior to this, the tests would always return incorrect passes due to the use of ".findBy..." returning a Promise that always .exists().

Testing

Test on app-project, on localhost

• Open any paused project with a results page, e.g. https://local.zooniverse.org:3000/projects/alexfitzpatrick/bradfords-industrial-heritage-in-photographs?env=production
• Examine the "See Results" link. It should be a valid link to a results page.

Status

Ready for review.

Note: if this gets approved while I'm on vacation, please go ahead and merge+deploy this.