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>
Add group-address `Client` implementation. Return instances of this
implementation from `ClientCache.Get` method.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>