invokefunction and invokescript RPC calls should support scoped signatures

[roman-khimov]

Summary or problem description
invokefunction and invokescript RPC calls support passing script hashes for verifying that are to be used by System.Runtime.CheckWitness syscall (thanks to neo-project/neo#335 and #214 changes). It's a very useful feature, but these hashes are not processed the way they will be processed when they're added as Cosigners for a transaction (and that's what is supposed to happen with a lot of these test invocations, trying first and then sending a real transaction) because transactions use scoped signatures since neo-project/neo#968 merge. It may affect the result of test invocation and lead to differences with execution on real network.

Do you have any solution you want to propose?
I propose replacing current script hashes parameter (which is just the last parameter for current invokefunction and invokescript that is supposed to be an array of hex-encoded 20-byte script hashes) with cosigners parameter that is to be represented as an array of JSON-serialized Cosigner structures (that are well-defined).

Example request using this format (similar to https://docs.neo.org/v3/docs/en-us/reference/rpc/latest-version/api/invokefunction.html):

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "invokefunction",
  "params": [
    "0x806b7fa0db3b46d6c42e1e1b0a7fd50db9d4a9b0",
    "transfer",
    [
      {
        "type": "Hash160",
        "value": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"
      },
      {
        "type": "Hash160",
        "value": "0x2916eba24e652fa006f3e5eb8f9892d2c3b00399"
      },
      {
        "type": "Integer",
        "value": "1000"
      }
    ],
    [
      {
        "account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569",
        "scopes": "CalledByEntry"
      }
    ]
  ]
}

Where in the software does this update applies to?

• RPC (HTTP)

[roman-khimov]

Side note: we have it now implemented as an extension in neo-go, so it accepts both an array of hashes (that are treated like cosigners with Global scope) and an array of proper Cosigners.

[superboyiii]

@roman-khimov #280 was merged, your issue should be solved.