Extension of dual fixing for single equations

[fwesselm]

• Following a discussion in Potential overhead reduction for dual fixing #2773, I am proposing to extend HPresolve::dualFixing to handle single equations (as described by Achterberg et al., Presolve Reductions in Mixed Integer Programming, see section 6.1).
• My test runs showed that the extension is not very effective (ratios of shifted geometric means of running times and numbers of nodes are very close to 1.0). However, the extension is relatively cheap, so I would be in favor of adding it anyway.
• I also modified HPresolve::enumerateSolutions to compute the overlap coefficient when comparing two sets of binary variables.

[codecov]

Codecov Report

❌ Patch coverage is 98.98990% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 80.39%. Comparing base (1df4aa5) to head (35c5bf6).
⚠️ Report is 47 commits behind head on latest.

Files with missing lines	Patch %	Lines
highs/presolve/HPresolve.cpp	98.98%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           latest    #2869      +/-   ##
==========================================
+ Coverage   80.35%   80.39%   +0.04%     
==========================================
  Files         348      348              
  Lines       86522    86675     +153     
==========================================
+ Hits        69527    69685     +158     
+ Misses      16995    16990       -5     

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[Opt-Mucca]

Code looks good! I've got the one open question and if that's simply me being paranoid then this should be good to merge.

[Opt-Mucca]

FYI (in case notifications for non-direct tags are turned off) @ZhaoWeiWang0319

[fwesselm]

Code looks good! I've got the one open question and if that's simply me being paranoid then this should be good to merge.

Thank you, @Opt-Mucca!

[ZhaoWeiWang0319]

Thanks, @Opt-Mucca!
I wasn't receiving notifications before you mentioned it, much appreciated!

I am really happy to see that the discussion being helpful.
Huge thanks to @fwesselm for the implementation and evaluation work!

[fwesselm]

Let me know if there are other questions or things to address here. Otherwise, I think it's good to merge.