Pointing to legacy endpoint for model configs

[dvince2]

We are currently in the midst of a major refactor on model-configurations and are changing how the endpoints will work. As this system gets integrated we've kept the old model config objects and endpoints active until we're ready to flip the switch.

Note that this PR should not be merged until HMI-Server is updated to use these endpoints correctly: DARPA-ASKEM/terarium#3802

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 81.95%. Comparing base (8b4507f) to head (1ec320f).
Report is 3 commits behind head on main.

Files	Patch %	Lines
src/SimulationService.jl	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #178      +/-   ##
==========================================
- Coverage   83.50%   81.95%   -1.55%     
==========================================
  Files           4        4              
  Lines         673      643      -30     
==========================================
- Hits          562      527      -35     
- Misses        111      116       +5     

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