Add test for mixed models (NLP)

[tmigot]

I catch a bug where with the current system calling hprod and hess allocate because the vector y is expected of size ncon and not nnln.

178

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.60 :tada:

Comparison is base (1b615ea) 93.40% compared to head (e90becc) 94.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #180 +/- ## ========================================== + Coverage 93.40% 94.00% +0.60% ========================================== Files 13 14 +1 Lines 1622 1651 +29 ========================================== + Hits 1515 1552 +37 + Misses 107 99 -8 ``` | [Impacted Files](https://app.codecov.io/gh/JuliaSmoothOptimizers/ADNLPModels.jl/pull/180?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers) | Coverage Δ | | |---|---|---| | [src/ad\_api.jl](https://app.codecov.io/gh/JuliaSmoothOptimizers/ADNLPModels.jl/pull/180?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers#diff-c3JjL2FkX2FwaS5qbA==) | `92.66% <100.00%> (+4.78%)` | :arrow_up: | ... and [6 files with indirect coverage changes](https://app.codecov.io/gh/JuliaSmoothOptimizers/ADNLPModels.jl/pull/180/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers)

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[github-actions[bot]]

Package name	latest	stable
CaNNOLeS.jl
DCISolver.jl
DerivativeFreeSolvers.jl
JSOSolvers.jl
NLPModelsIpopt.jl
OptimizationProblems.jl
Percival.jl
QuadraticModels.jl
SolverBenchmark.jl
SolverTools.jl