Enhance config types and summary

[svartkanin]

Enhances the configuration handling logic as well as the summary

• Introduced a new abstract class type SubConfig that needs to be inherited by all sub configurations.
  • Mandates the implementation of json() (which all do already), and the new summary() method which provides a short summary of the respective configuration element
• Refactored the configuration handling in args.py to use a new ArchConfigType and split the configurations by plain and sub config
• Enhanced the summary implementation to use the rich table which handles formatting automatically