Update core API store support to return errors

[aaronc]

Core API store support was added in #14326, but we changed the API to return errors in #14622 so now we have to update the implementation in runtime and also update the backport (#14326).

[tac0turtle]

to make this happen do you see us breaking the interface in the store package as well?

[aaronc]

to make this happen do you see us breaking the interface in the store package as well?

No, just what core API provides (for now)