feat!(API): add callback(result) to lua API

[alfaix]

In this PR I add callback(result) as the last parameter to most API calls, and:

1. Make sure it is always called exactly once, be that in case of success or failure
2. Fix a bug with Result type: its new method was setting attributes on the class instead of the object
3. Fix a bug with Types type: SUCCESS was 1 when there are places in code that assume that it is 0
4. Add a couple of error messages

I tested this locally - to an extent, let me know if there is some kind of proper procedure to know it's working.

RESOLVES: #245

[Civitasv]

LGTM. This is indeed improve the API quality, thanks for your work! I think you should also document it somewhere. Maybe create a API file in the docs folder.