SourceMap Support

Sourcemaps are currently not supported meaning that stack traces will be from transpiled JS sources. This is not ideal for debugging purposes.

The parcel bundler has implemented support for source maps in a rust package. Its not available on crates.io but the logic of deserializing a sourcemap is not very complicated.

https://github.com/parcel-bundler/source-map/tree/master/parcel_sourcemap

Here is explanation of sourcemaps:
https://www.bugsnag.com/blog/source-maps/

If this could be implemented without pulling in serde json dependency it would be ideal since the QuickJS engine already has a build in json parser

Start by reviewing the linked parcel_sourcemap implementation and the QuickJS JSON parser mentioned in the issue. Trace how LLRT currently produces stack traces, then determine where source-map deserialization and lookup belong. Done means stack traces refer to original sources rather than transpiled JavaScript, ideally without adding serde_json.

Written by the indexing model from the issue text.