Chiselstrike Errors should be more descriptive and user can throw Chisel errors

[BearLemma]

Our endpoints currently don't provide a good way to handle errors.

1. We don't include any numerical codes in the errors and don't propagate them nicely to the response. In case of an error, the response could automatically include body: {message: failed to locate user of id blabla, code: 7}
2. We should expose ChiselError classes so that users don't have to write their boilerplate code to get nice error handling.

@luisfvieirasilva @ricardodalarme @honzasp did I get it right?

[BearLemma]

Btw it's partially related to https://github.com/chiselstrike/chiselstrike/issues/1800

[MarinPostma]

I'll work on that ASAP