Hyper and rust-url disagree about how to parse URLs

[asajeffrey]

In the http_loader we convert URLs from rust-url to hyper, for example when constructing a Referer at

servo/components/net/http_loader.rs

Line 886 in 6ed204d

.typed_insert::<Referer>(http_request_referrer.to_string().parse().unwrap()),

The problem is that this may fail, because rust-url and hyper have different parsers, for example rust-url accepts http://"empty_script.js/?id=5\\%22 but hyper doesn't. This came up during testing. #24148 (comment)