chore(cause): added error cause

[dreamsparkx]

related: krakenjs/confit#93

[jonathansamines]

After closely looking at this, I think right now, we are only dealing with synchronous handlers function handler(input), but we actually need to do something similar for asynchronous handlers, which have a different signature function handler(input, cb).

I think we'll need to do wrap L201 with a callback that simply wraps handler and decorates errors with the additional information before propagating. Something like:

- return handler
+return function handl(...args) {
+   const next = args[args.length - 1];
+
+   function cb(err, ...ar) {
+        return next(new Error('error with more info', { cause: err }), ...ar);
+   }
+
+    args[args.length - 1] = cb;
+
+    return handler(...args);
+}

The changes should look roughly like that, but I'd test and update/add new tests if necessary to ensure those changes behave as intended.

[dreamsparkx]

added more cases