It is useless process since subnet owner is able to delete subnet without an
Alphabet approval. The Alphabet should only validate netmap state after
removal:
1. Update nodes' attributes if they were included in the deleted subnet;
2. Remove nodes without any subnet entrance.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Define notification events, implement parsers. Add morph client of
Subnet contract. Listen, verify and approve events in Inner Ring app.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
