Feature request: Breakpoint support (for debugging)!

[eirikb]

Describe the solution you'd like
It would be great if end users could add breakpoints to their code to debug, like they can in Deno.

Describe alternatives you've considered
From my investigation this isn't very hard to add, since it is already in Deno.
Just needs to set RuntimeOptions.inspector = true.
But, one must also have an inspector server, and from what I can tell this is part of deno_runtime.

And so there are probably two (or three) options:

1. Add deno_runtime as dependency, or
2. Just copy/paste in this: https://github.com/denoland/deno/blob/main/runtime/inspector_server.rs
3. Don't add the web server thing at all, expect end users to bring their own. Possible, extremely little change needed in rustyscript, but not very user friendly.

I could try to make a PR if you like - I have this implemented on my fork already and we are rolling it out today as a new feature.