Operations with Any

[blegat]

Supporting Any causes some issues, see for instance JuliaAlgebra/MultivariatePolynomials.jl#290

StarAlgebras.jl/src/arithmetic.jl

Line 78 in dd6c877

a::Any,

It'd like for StarAlgebras to try to have a cleaner solution for this and at some points, I'll probably replace the polynomial implementation of MultivariatePolynomials by StarAlgebras and at that point I'll stop support Any there too.
What we need is to support Union{Number,MOI.AbstractFunction,JuMP.AbstractJuMPScalar}.
We have two options:

1. Support Union{Number,MA.AbstractMutable}
2. Support Number and add support for MOI and JuMP functions using package extensions
   I feel that 2) is probably the cleanest solution.