With this change applied, libimagstore does not export backend
representing types anymore.
This change is necessar because when we want to switch the `StoreId`
implementation from "complex and stateful" to "Stateless and Cow<'_,
&str>", we need to be able to have a type which represents a "`StoreId`
plus the path of the Store itself".
This "the path of the Store itself" is passed around as reference, to
minimize runtime impact.
Because such a type should not be exported by the libimagstore crate, we
make it `pub(crate)` internally. But because the backend APIs also have
to use this type, we would export the (private) type in the APIs of the
backend.
Because of that we make the backend API also non-visible to crate users,
which also decreases the surface of the libimagstore API itself.
Besides:
Remove function `Link::with_base()` which is not needed anymore (was
used in tests only).
Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
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.
Also change that the implementation uses toml_query::set instead of
toml_query::insert.
Inserting values creates intermediate tables, set doesn't. And we really
want that convenience here, as the code is complex enough on its own.
