There is a need to define storage node's interface to remove objects from
the local storage.
Define `DropObjects` RPC in `ControlService`. Define `DropObjectsRequest` /
`DropObjectsResponse` structure of the request / response messages.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Add NetmapSnapshot rpc to ControlService protobuf definition. Recompile
proto files. Add required method to server structure.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>