[CONFIG] Unify implementations for ProvierConfig and ToolsetConfig

[manusa]

Description

#425 follow-up

Config has now ToolsetConfig and ProviderConfig which do essentially the same.

We want to consolidate this into a single interface (e.g. Extended) which provides the functionality.
Analyze if there's specific functionality to any of the approaches, but initially it seems that they are doing exactly the same. If not, check what the best approach is to provide the common functionality along with the specialized one for each approach.

This will likely create breaking changes downstream. Follow up with those.