Improve configuration management

[giffels]

The configuration management is missing reasonable error messages, which should be improved in the future.
In addition, it would be nice to add a possibilty to flag options as optional. This would help to differentiate "optional flag not present" from "real error".

[maxfischer2781]

Do you think it would be possible to transition from arbitrary Configurations to typed/annotated? That would allow to automatically create readers, validation and docs.

I've heard some good things about pydantic in that regard. Not sure if that fits our usecase completely, but could probably do the heavy lifting.

[giffels]

Honestly, I like that idea. I also heared about pydantic maybe we should take a closer look into that, how well this fits our usecase. Do you agree that configuration validation should be part of COBalD?

[maxfischer2781]

You are right, this would fit well into cobald. It seems generic enough to apply to all plugins and the cobald pipelines themselves.