Morph event structures defined in `pkg/morph/event` should only carry
notification values without any additional interpretation. All logical work
should be concentrated on app-side. Change `Bind.User` / `Unbind.User` to
return byte slice. Change `Bind.Keys` / `Unbind.Keys` to return `[][]byte`.
`ParseBind` / `ParseUnbind` don't decode data from now.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Neo-go does not use smartcontract.Parameter to return values
anymore, so it's convertes partly removed from neofs-node.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>