Remote packages out of experimental + improvements

[WebReflection]

The experimental_remote_packages flag has been a life-saver for anything MicroPython related, as it's otherwise hard to publish some official package that would work in both Pyodide and MicroPython.

In latest days, I've been porting/using remote packages in various occasions so I'd say it's time to make it official.

On top of that, specially for offline-first use cases, having relative or absolute paths would also help bootstrapping anything from either GitHub pages, static sites, and whatnot but currently the feature works only for fully remote URLs.

Proposal

• relax and resolve the package if:
  • it ends with either .toml or .json
  • starts with https?: or / or ./ or ../
• remove the flag and always resolve packages this way

@ntoll thoughts? This helps also the Positron story or, in general, debugging and development from local to remote.

[ntoll]

This sounds like a good idea.