[FR]: assets support for rspack "publicDir"

[jbedard]

Currently absolute paths map to the repo root.

Maybe absolute paths for assets (only jsx assets?) should map to:

1. the parent directory containing a package.json, falling back to the worksapce root
2. the parent "assets directory" if configured via
   a. a js_assets_dir directive
   b. rspack publicDir (probably won't support this and you must duplicate this config in a directive)

See rspack static assets for more info about asset resolution

[Aghassi]

While I currently don't need this feature, I'm commenting here as having a configurable path would be nice to have if necessary for those use cases.