fix: Enable golden-layout jest test and fix broken EventUtils test

[mattrunyon]

Noticed we had migrated a test into golden-layout, but it never ran. At a future point I then broke the test (not cleaning up event handlers on unmount), but it wasn't running so it wasn't caught.

This enables the test and fixes the broken logic so the test passes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 44.64%. Comparing base (1c9a8ed) to head (2f3ca18).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2467      +/-   ##
==========================================
- Coverage   47.27%   44.64%   -2.64%     
==========================================
  Files         727      755      +28     
  Lines       39767    42304    +2537     
  Branches     9949    10825     +876     
==========================================
+ Hits        18800    18886      +86     
- Misses      20956    23364    +2408     
- Partials       11       54      +43     

Flag	Coverage Δ
unit	44.64% <100.00%> (-2.64%)	⬇️

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[bmingles]

LGTM