chore: Fix several style lints (#17488)

It's not comprehensive enough to start linting on `style` group, but
hey, it's a start.

Release Notes:

- N/A

crates/extension_api/src/extension_api.rs

@@ -182,7 +182,7 @@ static mut EXTENSION: Option<Box<dyn Extension>> = None;
 pub static ZED_API_VERSION: [u8; 6] = *include_bytes!(concat!(env!("OUT_DIR"), "/version_bytes"));
 
 mod wit {
-    #![allow(clippy::too_many_arguments)]
+    #![allow(clippy::too_many_arguments, clippy::missing_safety_doc)]
 
     wit_bindgen::generate!({
         skip: ["init-extension"],

crates/extension_api/src/http_client.rs

@@ -17,7 +17,7 @@ impl HttpRequest {
 
     /// Executes the [`HttpRequest`] with [`fetch_stream`].
     pub fn fetch_stream(&self) -> Result<HttpResponseStream, String> {
-        fetch_stream(&self)
+        fetch_stream(self)
     }
 }
 
@@ -31,6 +31,12 @@ pub struct HttpRequestBuilder {
     redirect_policy: RedirectPolicy,
 }
 
+impl Default for HttpRequestBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl HttpRequestBuilder {
     /// Returns a new [`HttpRequestBuilder`].
     pub fn new() -> Self {