Add configuration interface

[longemen3000]

is necessary to add a configuration interface, to define tolerance, max iterations, and other things

[longemen3000]

i'm thinking how to implement this, for now i've added two options via kwargs in the solver

• verbose::Bool=false : prints what the alg is doing (working on it)
• test_phase::HelmholtzPhase=nothing you can pass an an initial point and checks if the point is a feasible starting point (working, maybe change name?)
• local_iters::Int =10*length(x) controls the amount of local optimizations

tolerance is a feasible option to add, iterations is similar to local_iters (change name to local_iterations?)
Other feasible option is to shutdown the global optimizer.