We have smartcontract.ParameterPair structure that can be properly
marshalled and passed to RPC server as an element of smartcontract.Map
structure. However, RPC server can't unmarshal map values properly
without this change.
This change is compatible with C# node.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.