Implement optimization with ASCO for Ngspice mode

[ra3xdh]

Ngspice supports optimization using ASCO. See https://asco.sourceforge.net/doc/ASCO.html It should be technically possible to implement optimization from within Qucs-S. Now Qucs-S supports optimization with ASCO only using Qucsator. It's need to expand this feature for Ngspice too. This could be a good BS or MS thesis project for someone. I cannot perform this task myself in the near future, but I can provide guidance.