GetRawNotaryTransaction returns a fallback or main transaction that was
previously added to the memory pool by P2PNotaryRequest. This function
invokes the RPC server's `getrawnotarytransaction` method.
GetRawNotaryPool returns hashes from all the verified transactions,
including both main and fallback transactions. This function invokes
the RPC server's `getrawnotarypool` method.
Also, these functions were added to doc.go.
Signed-off-by: Tatiana Nesterenko <tatiana@nspcc.io>