Enable function sets of function sets in the arrays encoding

[rodrigo7491]

• Tests added for any new code
• Ran make fmt-fix (or had formatting run automatically on all files edited)
• Documentation added for any new functionality
• Entry added to UNRELEASED.md for any new functionality

See title. Closes #1774.

[codecov-commenter]

Codecov Report

Merging #1775 (e8ed78d) into unstable (f38eb79) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##           unstable    #1775      +/-   ##
============================================
+ Coverage     76.81%   76.85%   +0.04%     
============================================
  Files           383      383              
  Lines         11837    11849      +12     
  Branches        548      553       +5     
============================================
+ Hits           9092     9107      +15     
+ Misses         2745     2742       -3     

Impacted Files	Coverage Δ
...rsyte/apalache/tla/bmcmt/smt/Z3SolverContext.scala	81.81% <100.00%> (+0.55%)	⬆️
...he/io/annotations/parser/CommentPreprocessor.scala	96.70% <0.00%> (+1.09%)	⬆️
.../at/forsyte/apalache/tla/bmcmt/types/package.scala	58.13% <0.00%> (+2.32%)	⬆️
...a/at/forsyte/apalache/tla/lir/TlaLevelFinder.scala	100.00% <0.00%> (+2.63%)	⬆️

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[konnov]

Looks good!