Auto merge of #13058 - malisas:malisa-responseAPI, r=Manishearth,jdm

Response API

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This PR adds the [dom::Response](https://fetch.spec.whatwg.org/#response-class) implementation and addresses #11896.

The relevant passing tests` expectations have been updated.

In order to allow non-UTF-8-encoded status messages, `net_traits::response::Response`'s `raw_status` field has been changed from type [`Option<RawStatus>`](https://doc.servo.org/hyper/http/struct.RawStatus.html) to type `Option<(u16, Vec<u8>)>`. As a result, a few other files which rely on the `raw_status` field were affected and updated.

TODOs:
- The `body` and `trailer` methods. Relies on implementation of `ReadableStream` and `Promise`s.
- Similarly, replace the dummy constructor `_body: Option<USVString>` argument with `body: ResponseBodyInit`.
- Currently, whenever `r's response's header list` or `r's Headers object` are mentioned, I always modify the `headers_reflector` field (of type dom::Headers, or `r's Headers object`) and not the corresponding hyper::Headers list in the net_traits::Response field. A completely accurate interpretation of the spec might consider making both of these lists the same thing via a reference. [Discussion](https://github.com/whatwg/fetch/issues/358) was [had](https://github.com/servo/servo/pull/12884).

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- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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1 files changed, 1 insertions, 2 deletions

diff --git a/components/net/blob_loader.rs b/components/net/blob_loader.rs
index 5cad922802a..1fe15d9a4a5 100644
--- a/components/net/blob_loader.rs
+++ b/components/net/blob_loader.rs
@@ -5,7 +5,6 @@
 use filemanager_thread::{FileManager, UIProvider};
 use hyper::header::{DispositionType, ContentDisposition, DispositionParam};
 use hyper::header::{Headers, ContentType, ContentLength, Charset};
-use hyper::http::RawStatus;
 use hyper_serde::Serde;
 use ipc_channel::ipc;
 use mime::{Mime, Attr};
@@ -72,7 +71,7 @@ fn load_blob<UI: 'static + UIProvider>
                     charset: charset.map(|c| c.as_str().to_string()),
                     headers: Some(Serde(headers)),
                     // https://w3c.github.io/FileAPI/#TwoHundredOK
-                    status: Some(Serde(RawStatus(200, "OK".into()))),
+                    status: Some((200, b"OK".to_vec())),
                     https_state: HttpsState::None,
                     referrer: None,
                 };