Neo Legacy used migration mechanism to update contracts.
N3 provides update method in native management contract.
Therefore, it makes sense to rename `Migrate` to `Update`.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
As soon as migration required changes in memory, we
need bigger scope. Otherwise in requires two step migration
which is unpleasant and annoying.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Processing contract deployed in main chain and processes
multi signature invocations of NeoFS contract by
verifying multi signature and paying for it.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
