Update JuMP syntax to use the new nonlinear interface

[frapac]

I had to comment out the tests checking that the formulation in JuMP matches those in ADNLPModels.

Apparently, the problem arises when we have ScalarQuadraticFunction in the MOI model. Maybe related to: https://github.com/JuliaSmoothOptimizers/NLPModelsJuMP.jl/pull/102

[tmigot]

Thanks a lot @frapac for the PR. NLPModelsJuMP still doesn't support the quadratic constraints, we lagged behind probably because we did not have a big usage of it. With the new nonlinear JuMP interface, I think we will try to add this quickly. I propose we wait a bit for this PR.