https://github.com/nspcc-dev/neo-go/pull/2435 breaks compatibility
between newer RPC clients and older RPC servers with the following
error:
```
failed to get network magic: json: cannot unmarshal string into Go struct field Protocol.protocol.initialgasdistribution of type int64
```
This behaviour is expected, but we can't allow this radical change.
Thus, the following solution is implemented:
1. RPC server responds with proper non-stringified
InitialGasDistribution value. The value represents an integral
of fixed8 multiplied by the decimals.
2. RPC client is able to distinguish older and newer responses. For
older one the stringified value without decimals part is
expected. For newer responses the int64 value with decimal part
is expected.
The cludge will be present in the code for a while until nodes of
version <=0.98.3 become completely absolete.
Implement a way to check if tx has been persisted on blockchain and
to get general info about transaction. Much more convenient than
handwritten curl queries.
Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
1. Initialization is performed via `Blockchain` methods.
2. Native Oracle contract updates list of oracle nodes
and in-fly requests in `PostPersist`.
3. RPC uses Oracle module directly.
We should return verbose transaction in case if it is in the mempool
from `getrawtransaction`. We also shouldn't return height from
`gettransactionheight` in case if transaction is in the mempool.
