DM-52339: update test helpers to enable custom dimension universes

[TallJimbo]

Checklist

• ran Jenkins
• ran and inspected package-docs build
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.41%. Comparing base (d007217) to head (4127994).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@                 Coverage Diff                  @@
##           tickets/DM-51850     #516      +/-   ##
====================================================
- Coverage             88.42%   88.41%   -0.02%     
====================================================
  Files                   138      138              
  Lines                 18423    18423              
  Branches               2194     2194              
====================================================
- Hits                  16290    16288       -2     
- Misses                 1616     1617       +1     
- Partials                517      518       +1     

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