Fix instantiateStreaming usage on web (#3209)

### What

This is a fix for:

![image](https://github.com/rerun-io/rerun/assets/1665677/370f9e51-aa82-4359-aa4b-dd72cf942a7a)

The WASM was being fetched in full before instantiation (the `await
res.blob()`), so we weren't getting the benefit of
`instantiateStreaming`. This PR should also improve loading times on
slow connections.

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested [demo.rerun.io](https://demo.rerun.io/pr/3209) (if
applicable)

- [PR Build Summary](https://build.rerun.io/pr/3209)
- [Docs
preview](https://rerun.io/preview/51c233aa61893ece69b0bb0695309b23fef469b5/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/51c233aa61893ece69b0bb0695309b23fef469b5/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://ref.rerun.io/dev/bench/)
- [Wasm size tracking](https://ref.rerun.io/dev/sizes/)

scripts/ci/demo_assets/static/index.js

@@ -104,14 +104,20 @@ function load_wasm() {
           }
           controller.close();
         },
-      })
+      }),
+      {
+        status: response.status,
+        statusText: response.statusText,
+      }
     );
-    const wasm = await res.blob();
 
-    // Don't fade in the progress bar if we haven't hit it already.
-    clearTimeout(timeoutId);
+    for (const [key, value] of response.headers.entries()) {
+      res.headers.set(key, value);
+    }
 
-    wasm_bindgen(URL.createObjectURL(wasm)).then(on_wasm_loaded).catch(on_wasm_error);
+    wasm_bindgen(res)
+      .then(() => (clearTimeout(timeoutId), on_wasm_loaded()))
+      .catch(on_wasm_error);
   }
 
   wasm_with_progress();

web_viewer/index.html

@@ -264,14 +264,17 @@
                         }
                         controller.close();
                     },
-                }));
-                const wasm = await res.blob();
+                }), {
+                    status: response.status,
+                    statusText: response.statusText,
+                });
 
-                // Don't fade in the progress bar if we haven't hit it already.
-                clearTimeout(timeoutId);
+                for (const [key, value] of response.headers.entries()) {
+                    res.headers.set(key, value);
+                }
 
-                wasm_bindgen(URL.createObjectURL(wasm))
-                    .then(on_wasm_loaded)
+                wasm_bindgen(res)
+                    .then(() => (clearTimeout(timeoutId), on_wasm_loaded()))
                     .catch(on_wasm_error);
             }
 

web_viewer/index_bundled.html

@@ -262,14 +262,17 @@
                         }
                         controller.close();
                     },
-                }));
-                const wasm = await res.blob();
+                }), {
+                    status: response.status,
+                    statusText: response.statusText,
+                });
 
-                // Don't fade in the progress bar if we haven't hit it already.
-                clearTimeout(timeoutId);
+                for (const [key, value] of response.headers.entries()) {
+                    res.headers.set(key, value);
+                }
 
-                wasm_bindgen(URL.createObjectURL(wasm))
-                    .then(on_wasm_loaded)
+                wasm_bindgen(res)
+                    .then(() => (clearTimeout(timeoutId), on_wasm_loaded()))
                     .catch(on_wasm_error);
             }