Adding deprecation warning for has_phase_equilibrium but only 1 phase

[andrewlee94]

Required for #1225

Summary/Motivation:

This PR adds a deprecation warning for backward compatibility for cases where a control volume is set to include phase equilibrium terms but the associated property package only has a single phase.

Changes proposed in this PR:

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[codecov]

Codecov Report

Patch coverage: 88.23% and project coverage change: -0.01% ⚠️

Comparison is base (68e2c4f) 76.84% compared to head (e08105b) 76.84%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1236      +/-   ##
==========================================
- Coverage   76.84%   76.84%   -0.01%     
==========================================
  Files         390      390              
  Lines       61918    61924       +6     
  Branches    11400    11400              
==========================================
+ Hits        47580    47583       +3     
- Misses      11871    11875       +4     
+ Partials     2467     2466       -1     

Files Changed	Coverage Δ
idaes/core/base/control_volume0d.py	89.38% <77.77%> (+0.04%)	⬆️
idaes/core/base/control_volume1d.py	90.21% <100.00%> (+0.03%)	⬆️

... and 1 file with indirect coverage changes

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