Before we extracted the store configuration from the configuration
toml::Value object and passed it to the store.
This is unecessary overhead.
Now we pass the whole configuration object and let the store extract the
required values.
This merge solved a _LOT_ of conflicts and was a rather complicated one,
as parts of the conflict-resolution involved rewriting of half the
stuff.
This merge commit fixes all the things so a `cargo check --all`
succeeds, but I did not yet check whether tests run without failure.
