Refactor Z3SolverContext cellCache

[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

This PR refactors updates to cellCache to not happen during iterations. Closes #1595.

[konnov]

Looks good!

[codecov-commenter]

Codecov Report

Merging #1703 (d06a4c7) into unstable (7823b14) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##           unstable    #1703   +/-   ##
=========================================
  Coverage     75.31%   75.32%           
=========================================
  Files           357      357           
  Lines         11541    11541           
  Branches        576      595   +19     
=========================================
+ Hits           8692     8693    +1     
+ Misses         2849     2848    -1     

Impacted Files	Coverage Δ
...rsyte/apalache/tla/bmcmt/smt/Z3SolverContext.scala	81.18% <100.00%> (ø)
...he/io/annotations/parser/CommentPreprocessor.scala	96.70% <0.00%> (+1.09%)	⬆️

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