Optional API to convert to http::Uri

[Redfire75369]

Rationale

The simplest way to convert from a url::Url to a http::Uri currently is to turn it into a string and then parse it again. It would be helpful if there was an API to do this conversion directly, instead of necessitating another round of parsing

Proposal

With a feature flag called http, the dependency http can be added. When the http feature is active, a function can be exposed which does the conversion from url's internal structure to that of http::Uri's.

[valenting]

I'm not totally convinced this is something that belongs in the url crate. I'd rather keep dependencies to a minimal, and even if this is behind a feature gate, it still needs CI testing. I would suggest a crate that depends on both rust-url and http that uses Builder to create a new http uri from parts.

[Redfire75369]

I understand your concerns, perhaps a Builder API for this crate may be more helpful then, so that the conversion could be done both ways relatively efficiently.

[Kinrany]

Are URIs truly deprecated in some sense? The URL standard by WHATWG claims that a single algorithm is used for both and that they aim to deprecate URIs as a term in favor of URL, but I don't quite get how that could be possible when URIs are a superset of URLs.