Fix the following linter warning:
```
pkg/rpc/client/wsclient.go:99:18 govet copylocks: literal copies lock value from *cl: github.com/nspcc-dev/neo-go/pkg/rpc/client.Client contains sync.RWMutex
```
1. Keep initDone check only for the places where cache is directly accessed.
We don't need to check it in other places, otherwise we have a mess of
duplicating checks.
2. Fix bug in code related to block deserialisation. There's no magic, so
checking that initialisation is done is not enough for proper block
deserialisation. We need to manually fill StateRootEnabled field.
3. Since transaction doesn't need network magic to compute its hash, we don't
need to perform Client initialisation before transaction-related requests.
4. Check that cache is initialised before accessing network magic.
5. Refactor the way Policy contract hash is fetched for Client requests.
We don't really need Client initialisation for that, it's OK to fetch Policy
hash on-the-fly.
`StateRootInHeader` is duplicated similarly to `Network`.
It will be removed in future as it is surely a protocol parameter.
Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
It's not needed any more with Go 1.13 as we have wrapping/unwrapping in base
packages. All errors.Wrap calls are replaced with fmt.Errorf, some strings are
improved along the way.
It doesn't affect anything yet, but it's going to be used in the future for
network-specific behavior. It also renames short '--timeout' form to '-s'
avoiding conlict with '-t' used for '--testnet'.
1. closes#841
2. Commented out test cases where binary transaction are used.
These test cases marked with `TODO NEO3.0: Update binary` and need to be
updated.
3. Updated other tests.
4. Added cache to calculateValidUntilBlock() RPC-client method.
