Add file for simplified minimization

• For likelihood, n_samples, newton_convergence, ... also support function that takes iteration index and returns the respective value (for dynamic optimization)
• Add support for constants (also potentially variable during optimization)
• Latent: Do not save hdf5
• 2d samples einzeln plotten (max. 20 oder so)
• Figure out how to automatically visualize residuals
• Add slot for ground truth
• Add tests
• Support constants and point estimates with domain errors

!710 (merged) is a part of this one. It may either be merged first or automatically be closed by merging this one.