Update NNS contract

[alexvanin]

After nspcc-dev/neo-go#2166 get new version from neo-go and write migrating routine. We expect that NNS contract stores TXT records about NeoFS contracts:

• alphabet0.neofs
• alphabet1.neofs
• alphabet2.neofs
• alphabet3.neofs
• alphabet4.neofs
• alphabet5.neofs
• alphabet6.neofs
• audit.neofs
• balance.neofs
• container.neofs
• neofsid.neofs
• netmap.neofs
• proxy.neofs
• reputation.neofs

See more details about NNS contract initialization there: https://github.com/nspcc-dev/neofs-node/blob/master/cmd/neofs-adm/internal/modules/morph/initialize_nns.go