Use Hessian approximation in CyIpopt when grey-box without Hessian is present

[Robbybp]

Fixes #3891

Changes proposed in this PR:

• Set (potentially override) hessian_approximation=limited-memory in CyIpopt solver when the model contains a grey-box that doesn't support Hessians
• Log a warning if this happens and the user had set hessian_approximation=exact
• Add a has_hessian_support method to PyomoNLPWithGreyBoxBlocks (previously only existed on _ExternalGreyBoxAsNLP, although the former has a private _has_hessian_support attribute)

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[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.93%. Comparing base (6baac63) to head (5ac3a48).

Files with missing lines	Patch %	Lines
...trib/pynumero/algorithms/solvers/cyipopt_solver.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3892      +/-   ##
==========================================
- Coverage   89.93%   89.93%   -0.01%     
==========================================
  Files         902      902              
  Lines      106393   106399       +6     
==========================================
+ Hits        95683    95685       +2     
- Misses      10710    10714       +4     

Flag	Coverage Δ
builders	29.21% <50.00%> (+0.01%)	⬆️
default	86.23% <83.33%> (?)
expensive	35.65% <50.00%> (?)
linux	87.38% <83.33%> (-2.04%)	⬇️
linux_other	87.38% <83.33%> (-0.01%)	⬇️
oldsolvers	28.12% <16.66%> (+0.01%)	⬆️
osx	82.73% <33.33%> (+0.01%)	⬆️
win	85.80% <83.33%> (-0.01%)	⬇️
win_other	85.80% <83.33%> (-0.01%)	⬇️

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