Upgrade NeoFS API Go library to version with status returns. Make all API
clients to pull out and return errors from failed statuses. Make signature
service to respond with status if client version supports it.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `NetworkInfo` calls on full stack of Netmap services. Current
epoch is read from node local state, magic number is read via `MagicNumber`
call of morph client.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
