[UX] Update wizard titles are inconsistent (and can be confusing)

[jenlampton]

Description of the bug

This is a follow-up to #6805 which is a follow-up to #2409

Steps To Reproduce

Run site updates, step through each step of the wizard.

Expected behavior

I would expect that the "page title" (or heading) on the modal would update to match the progress indicated down the left sidebar.

Recommendation

I wasn't fast enough to get a screenshot of "Updating..."

Additional information

Backdrop CMS: 1.30.x-dev
Installation profile: standard
PHP version: 8.1.30
Drupal 7 compatibility: on
Database server: 10.4.34-MariaDB-1:10.4.34+maria~ubu2004-log
Web server: nginx/1.26.2

[jenlampton]

I'm not sure how I feel about having "Update Backdrop CMS" in each title, but without "Update" it's not entirely clear what the wizard is doing, and without "Backdrop CMS" you don;t really know you are updating -- do either of these things matter? I dunno!