[KNITRO] Add warm start support

[eminyouskn]

Fixes # .

Summary/Motivation:

This PR implements the warm-start procedure for the KNITRO solver.

Changes proposed in this PR:

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.12%. Comparing base (787c6ff) to head (3115e08).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3833   +/-   ##
=======================================
  Coverage   90.12%   90.12%           
=======================================
  Files         905      905           
  Lines      107490   107505   +15     
=======================================
+ Hits        96873    96890   +17     
+ Misses      10617    10615    -2     

Flag	Coverage Δ
builders	29.13% <20.00%> (+<0.01%)	⬆️
default	86.46% <100.00%> (?)
expensive	35.21% <20.00%> (?)
linux	87.60% <20.00%> (-2.02%)	⬇️
linux_other	87.60% <20.00%> (-0.01%)	⬇️
oldsolvers	28.08% <20.00%> (+<0.01%)	⬆️
osx	82.98% <20.00%> (-0.01%)	⬇️
win	85.51% <20.00%> (-0.02%)	⬇️

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[michaelbynum]

This PR looks great, but it raised a broader design discussion for solver configs (see #3933 ). We are trying to figure out how to have common config options among subsets of solvers. For this PR, I think we just rename use_start to be knitro_use_warmstart so that it is clear that this option is specific to knitro. With that change, I think this will be ready to go.

Change was made

[blnicho]

I found one small typo. Assuming there are no other edits to make on this, we can fix the typo right before merging without waiting for tests to run again.