Add timeout support for IIS search

[haman80]

Add timeout support to getIIS

• Introduced a new iis_time_limit option to distinguish IIS search limits from the time_limit option
• Updated deletion filtering to return a partial IIS when the time limit is reached
• Added new model status kIisModelStatusTimeLimit

Improve handling of unexpected model statuses

• Temporarily modify options that may interfere with IIS search, including: simplex_iteration_limit, objective_bound, allow_unbounded_or_infeasible, Callbacks
• Updated getIisInterface to first establish infeasibility prior to elastic filtering or deletion filtering; abort IIS computation if the model is not confirmed infeasible
• After confirming infeasibility, attempt elastic filtering if requested; if it fails due to an unknown status, fall back to deletion filtering over the full set of row and column bounds
• Enhanced deletion filtering to skip bounds whose removal results in an unknown model status and return a partial IIS if possible

Enhancements to HighsIis

• Extended HighsIisInfo to track min, max, and mean iteration counts and LP solve times
• Centralize responsibility for updating these metrics
• Added helper methods determineBoundStatus, and processBoundRelaxation to reduce duplicated logic and improve maintainability

[jajhall]

@haman80 I've cleared the merge conflicts and pushed to Git

[codecov]

Codecov Report

❌ Patch coverage is 78.94737% with 52 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.36%. Comparing base (06309ae) to head (1b42c30).
⚠️ Report is 1 commits behind head on latest.

Files with missing lines	Patch %	Lines
highs/lp_data/HighsInterface.cpp	73.64%	34 Missing ⚠️
highs/lp_data/HighsIis.cpp	78.75%	17 Missing ⚠️
highs/lp_data/HighsOptions.h	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           latest    #2870      +/-   ##
==========================================
- Coverage   80.37%   80.36%   -0.02%     
==========================================
  Files         348      348              
  Lines       86600    86695      +95     
==========================================
+ Hits        69609    69674      +65     
- Misses      16991    17021      +30     

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