Establish an actual optimizer to replace brute-force sweep

[Konohana0608]

The new optimizer should replace our current brute-force sweeper. Since it is multigoal optimization, the expected result should be a set of Pareto-efficient setups from which the user can select the one with the metrics that suit them best.

• Discussion with Cedric to gauge the scope of the problem
• pass needed data to Cedric #1803
• work on Gaussian Process Interpolation
• Fit response surface with limited evaluated points
• Write a test for the new functionality
• Implement the optimizer to replace the current sweeper
• remove electrode selector. Include model and target selection in the post-processor
• reconsider the Pareto front plot since it might not make sense to fit a Pareto front through points that are themselves all part of a Pareto front
• test the new optimizer on staging
• update tutorial
• release