Align Ergo throw/enforce errors with the standard Accord Project Error hierarchy

[jeromesimeon]

Is your feature request related to a problem? Please describe.
When a clause throws an error (either through an enforce expression or as an explicit throw in the logic), that error is caught after logic execution and turned into a low-level JavaScript error with a string.

It would be nice if the error being thrown in JavaScript was made part of the standard Accord Project error model (see https://docs.accordproject.org/docs/ref-errors.html).

The code is currently located in the Ergo runtime here:

ergo/backends/javascript/ergo-runtime.js

Line 851 in 7e8a925

function unwrapError(result) {

Describe the solution you'd like
A new kind of Accord Project exception for Logic errors (LogicException ?) in https://docs.accordproject.org/docs/ref-errors.html.

Change the runtime behaviour to raise one of those.

Maybe better location information, and details notably for enforce exceptions.