fix: FIT-411: Child Choices are disabled when leafsOnly is used

[niklub]

Fixing the error where child nodes are not selectable due to Taxonomy provided via $values with leafsOnly="true".

Example:

Three nested choices are leaves, they have empty children, but they are disabled and look as nodes.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.02%. Comparing base (84fb120) to head (ab0b71e).
⚠️ Report is 8 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8146      +/-   ##
===========================================
- Coverage    70.27%   66.02%   -4.25%     
===========================================
  Files          723      507     -216     
  Lines        52231    34244   -17987     
  Branches      8841     8841              
===========================================
- Hits         36705    22610   -14095     
+ Misses       15523    11631    -3892     
  Partials         3        3              

Flag	Coverage Δ
lsf-e2e	59.68% <0.00%> (+<0.01%)	⬆️
lsf-integration	55.40% <100.00%> (+<0.01%)	⬆️
lsf-unit	9.42% <50.00%> (ø)
pytests	?

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