Implement API methods of the Container contracts client corresponding
to the calls of the contract for storing the used space of the container
("putContainerSize", "getContainerSize", "listContainerSizes"). Extend
the wrapper over the client with methods abstracted from sidechen calls.
In particular, the method of storing the value will be used to record
the estimates of the used space of containers calculated by the network
participants.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
In #37 we've decided to remove length check, because smart contract would
fail on casting `nil` value from storage to `[]byte` producing FAULT state.
Apparently it does not fail, so we have to check length explicitly.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Container get wrapper implements container.Source interface
so it can be used in object service as container storage.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
