Define `NetworkInfo` rpc which can be used to read the recent NeoFS network
information. Request body is empty, response body contains NetworkInfo
message.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
This should be used as a handshake to know API Version supported by peer and to
update local netmap view in future.
Signed-off-by: Stanislav Bogatyrev <stanislav@nspcc.ru>
