Stop leaking isahc assumption (#18408)

Users of our http_client crate knew they were interacting with isahc as
they set its extensions on the request. This change adds our own
equivalents for their APIs in preparation for changing the default http
client.

Release Notes:

- N/A

crates/extension/src/extension_store.rs

@@ -664,7 +664,7 @@ impl ExtensionStore {
 
             let content_length = response
                 .headers()
-                .get(isahc::http::header::CONTENT_LENGTH)
+                .get(http_client::http::header::CONTENT_LENGTH)
                 .and_then(|value| value.to_str().ok()?.parse::<usize>().ok());
 
             let mut body = BufReader::new(response.body_mut());

crates/extension/src/wasm_host/wit/since_v0_1_0.rs

@@ -1,5 +1,5 @@
 use crate::wasm_host::{wit::ToWasmtimeResult, WasmState};
-use ::http_client::AsyncBody;
+use ::http_client::{AsyncBody, HttpRequestExt};
 use ::settings::{Settings, WorktreeId};
 use anyhow::{anyhow, bail, Context, Result};
 use async_compression::futures::bufread::GzipDecoder;
@@ -8,7 +8,6 @@ use async_trait::async_trait;
 use futures::{io::BufReader, FutureExt as _};
 use futures::{lock::Mutex, AsyncReadExt};
 use indexed_docs::IndexedDocsDatabase;
-use isahc::config::{Configurable, RedirectPolicy};
 use language::{
     language_settings::AllLanguageSettings, LanguageServerBinaryStatus, LspAdapterDelegate,
 };
@@ -297,10 +296,12 @@ fn convert_request(
     let mut request = ::http_client::Request::builder()
         .method(::http_client::Method::from(extension_request.method))
         .uri(&extension_request.url)
-        .redirect_policy(match extension_request.redirect_policy {
-            http_client::RedirectPolicy::NoFollow => RedirectPolicy::None,
-            http_client::RedirectPolicy::FollowLimit(limit) => RedirectPolicy::Limit(limit),
-            http_client::RedirectPolicy::FollowAll => RedirectPolicy::Follow,
+        .follow_redirects(match extension_request.redirect_policy {
+            http_client::RedirectPolicy::NoFollow => ::http_client::RedirectPolicy::NoFollow,
+            http_client::RedirectPolicy::FollowLimit(limit) => {
+                ::http_client::RedirectPolicy::FollowLimit(limit)
+            }
+            http_client::RedirectPolicy::FollowAll => ::http_client::RedirectPolicy::FollowAll,
         });
     for (key, value) in &extension_request.headers {
         request = request.header(key, value);

crates/extension/src/wasm_host/wit/since_v0_2_0.rs

@@ -1,5 +1,5 @@
 use crate::wasm_host::{wit::ToWasmtimeResult, WasmState};
-use ::http_client::AsyncBody;
+use ::http_client::{AsyncBody, HttpRequestExt};
 use ::settings::{Settings, WorktreeId};
 use anyhow::{anyhow, bail, Context, Result};
 use async_compression::futures::bufread::GzipDecoder;
@@ -8,7 +8,6 @@ use async_trait::async_trait;
 use futures::{io::BufReader, FutureExt as _};
 use futures::{lock::Mutex, AsyncReadExt};
 use indexed_docs::IndexedDocsDatabase;
-use isahc::config::{Configurable, RedirectPolicy};
 use language::{
     language_settings::AllLanguageSettings, LanguageServerBinaryStatus, LspAdapterDelegate,
 };
@@ -213,10 +212,12 @@ fn convert_request(
     let mut request = ::http_client::Request::builder()
         .method(::http_client::Method::from(extension_request.method))
         .uri(&extension_request.url)
-        .redirect_policy(match extension_request.redirect_policy {
-            http_client::RedirectPolicy::NoFollow => RedirectPolicy::None,
-            http_client::RedirectPolicy::FollowLimit(limit) => RedirectPolicy::Limit(limit),
-            http_client::RedirectPolicy::FollowAll => RedirectPolicy::Follow,
+        .follow_redirects(match extension_request.redirect_policy {
+            http_client::RedirectPolicy::NoFollow => ::http_client::RedirectPolicy::NoFollow,
+            http_client::RedirectPolicy::FollowLimit(limit) => {
+                ::http_client::RedirectPolicy::FollowLimit(limit)
+            }
+            http_client::RedirectPolicy::FollowAll => ::http_client::RedirectPolicy::FollowAll,
         });
     for (key, value) in &extension_request.headers {
         request = request.header(key, value);