Adding method error support

[L-Marcel]

Hi! I tried to create an approach to detect errors and I got the following result:

I created a folder with a new test as well:

Method example:

export async function getInfo(authorized: boolean): Promise<HostInfo> {
  if(!authorized) {
    return apiError(401, "Hey! You need to be authorized!", {
      requestedAt: new Date().toLocaleTimeString()
    });
  };

  return {
    now: new Date().toLocaleTimeString(),
    hostname: os.hostname(),
  };
}

Use case example:

React.useEffect(() => {
  const interval = setInterval(() => {
    getInfo(true).then(res => setInfo(res));
    getInfo(false).catch((err: RPCMethodError) => setError(err));
  }, 2000);
  return () => clearInterval(interval);
}, []);

Related issues: #19

Note: sorry for my English. I'm Brazilian. I thought the idea was amazing!

[L-Marcel]

I used npm link ../../ in "./examples/with-error" to run the example with the local version.