add net/url and net/http

[mflatt]

The net/url library builds on net/url-string and net/uri-code. It's in its own package, rhombus-url-lib plus rhombus-url.

The net/http library builds on http-easy. It's also in its own package, rhombus-http-lib plus rhombus-http.

So, to try out the change, use

raco pkg install rhombus-url-lib/ rhombus-url/ rhombus-http-lib/ rhombus-http/

in a Rhombus repo clone and accept dependency installs.

I think the general approach here is probably uncontroversial, so if there are no objections in the next day or so, I'll merge and register the packages, and then we can refine from there. (In other words, I don't think we're committed to "rare breaking changes" right away for new modules outside of #lang rhombus.)

[LiberalArtist]

Seems like the wrong link: maybe https://www.rfc-editor.org/rfc/rfc3986.html? (Racket links to https://www.ietf.org/rfc/rfc2396.txt: I'm not sure if there are relevant changes.)

[mflatt]

Thanks! It seems that the Racket docs link to RFC 2396 at the top and RFC 3986 at the url struct. I think the library is as consistent with RFC 3986 as RFC 2396 (though it's difficult to be sure), so I'll change to always refer to the newer one.