1. Initialization is performed via `Blockchain` methods.
2. Native Oracle contract updates list of oracle nodes
and in-fly requests in `PostPersist`.
3. RPC uses Oracle module directly.
In order to avoid dependency cycle at the next commits:
imports github.com/nspcc-dev/neo-go/pkg/config
imports github.com/nspcc-dev/neo-go/pkg/wallet
imports github.com/nspcc-dev/neo-go/pkg/vm
imports github.com/nspcc-dev/neo-go/pkg/smartcontract/nef
imports github.com/nspcc-dev/neo-go/pkg/config
