Support inequality constraints for NOMAD.jl

[ValentinKaisermayer]

Nomad expects c(x) <= 0, which is different to the interface in SciMLBase.jl: lb <= c(x) <= ub. This means that c(x) has to be evaluated and the concatenation of c(x) - ub and lb - c(x) has to be returned for all indices where ub and lb is finite.

Linear equality contraints are handled separately via A and b parameters in the problem.