fix: Restore "fix: nested lists roundtrip (#530)"

[buuhuu]

This restores commit e27ba08 which had been reverted in 88392b9.

The problem this caused last time with experience league got addressed, however we should do another round of testing.

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• make sure to link the related issues in this description
• when merging / squashing, make sure the fixed issue references are visible in the commits, for easy compilation of release notes

Related Issues

Fixes #529

Thanks for contributing!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (5be61ba) to head (4c1bb6a).

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #556   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            7         8    +1     
  Lines          797       825   +28     
  Branches         1         1           
=========================================
+ Hits           797       825   +28     

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[github-actions]

This PR will trigger a patch release when merged.

[auniverseaway]

FWIW: We (DA) would love to have this merged sooner rather than later.

[tripodsan]

@buuhuu did you check with experience-league if their code now works with collapsed lists?

[buuhuu]

I tested this with their dev env, but probably worth another iteration.