Updates to make HP queries return values instead of failing for higher pressures

[wandadars]

I was running a test case for a 1D counterflow diffusion flame at very high pressures using the Peng-Robinson equation of state, and the initial condition that used the HP equilibrate call return EoS failures. Codex 5.3 identified this as a possible reason for why the real/ideal gas mixed PREOS might be failing, and it did resolve the EoS that was happening for high pressure H-P equilibrate calls.

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[codecov]

Codecov Report

❌ Patch coverage is 63.82979% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.46%. Comparing base (f49df44) to head (dfa7d20).
⚠️ Report is 21 commits behind head on main.

Files with missing lines	Patch %	Lines
src/thermo/PengRobinson.cpp	66.66%	4 Missing and 3 partials ⚠️
src/thermo/RedlichKwongMFTP.cpp	66.66%	4 Missing and 3 partials ⚠️
src/thermo/MixtureFugacityTP.cpp	40.00%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2087      +/-   ##
==========================================
+ Coverage   77.34%   77.46%   +0.11%     
==========================================
  Files         451      451              
  Lines       52494    52791     +297     
  Branches     8847     8843       -4     
==========================================
+ Hits        40602    40895     +293     
- Misses       8917     8920       +3     
- Partials     2975     2976       +1     

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