H4C-246: Error handling in the JSONRpc module

[goce-h4]

This PR examines the approaches for throwing an error in the rpc methods .

1. The RPC methods will throw CodedRpcException.
2. The exception will be intercepted in the json rpc handler and it will be return as resolved promise with the error code and error object with message.

However the unit tests will need to test for errors like this:

return request(server.server)
      .post("/rpc/v1")
      .send({ method: "test.testError", params: { data: "hi" } })
      .expect(403)
      .expect(errorObj);

instead of testing the promise to fail like this:
expect(req).rejects.toEqual

We still need to see if and how we will use global exception handlers and how we will audit the errors which needs to be audited.

p.s Some of the console logs are left on purpose for testing.

[rm-h4]

I think that we should expect more error codes in future

[rm-h4]

pls delete console logs

[rm-h4]

please delete console logs