Error message quality: `parse` vs `iparse`

The usage of `parse` or `iparse` produce different error messages, since the former is excluding the information about the `JSONPath` of where the parse error happened.

This means that different functions (e.g. `fromJSON` and `decodeEither`) will produce error messages with different error quality.

I think it would be interesting to at least document which functions produce error messages which provide information on the error path and which ones do not