Ensure that Scopes can be properly parsed not only from the string
representation, but also from a single byte. transaction.Signer
is not affected (checked against the C# implementation), only
RPC-related signer scopes are allowed to be unmarshalled from byte.
Close#3059.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
See neo-project/neo#2622. The implementation is somewhat asymmetric (and not
very efficient) for binary/JSON encoding/decoding, but it should be
sufficient.
Follow missed change from neo-project/neo#1816 .
`None` may be used for any signer. Currently it is used
for sender to only pay fees, or to sign tx attributes.
