perf(ext/fetch): use new instead of createBranded (#20624)

This PR optimizes `fromInner*` methods of `Request` / `Header` /
`Response` used by `Deno.serve` and `fetch` by using `new` instead of
`ObjectCreate` from `createBranded`.

The "brand" is created by passing `webidl.brand` to the constructor
instead.


https://github.com/denoland/deno/blob/142449ecab20006c5cfd15462814650596bc034d/ext/webidl/00_webidl.js#L1001-L1005

### Benchmark
```js
const createBranded = Symbol("create branded");
const brand = Symbol("brand");
class B {
  constructor(init) {
    if (init === createBranded) {
      this[brand] = brand;
    }
  }
}

Deno.bench("Object.create(protoype)", () => {
  Object.create(B.prototype);
});

Deno.bench("new Class", () => {
  new B(createBranded);
});
```

```
cpu: 13th Gen Intel(R) Core(TM) i9-13900H
runtime: deno 1.37.0 (x86_64-unknown-linux-gnu)

benchmark                    time (avg)        iter/s             (min … max)       p75       p99      p995
----------------------------------------------------------------------------- -----------------------------
Object.create(protoype)       8.74 ns/iter 114,363,610.3    (7.32 ns … 26.02 ns)   8.65 ns  13.39 ns  14.47 ns
new Class                     3.05 ns/iter 328,271,012.2      (2.78 ns … 9.1 ns)   3.06 ns   3.46 ns    3.5 ns
```

1 files changed, 8 insertions, 2 deletions

diff --git a/ext/fetch/20_headers.js b/ext/fetch/20_headers.js
index 39127b1ec..a004daa89 100644
--- a/ext/fetch/20_headers.js
+++ b/ext/fetch/20_headers.js
@@ -40,6 +40,7 @@ const _headerList = Symbol("header list");
 const _iterableHeaders = Symbol("iterable headers");
 const _iterableHeadersCache = Symbol("iterable headers cache");
 const _guard = Symbol("guard");
+const _brand = webidl.brand;
 
 /**
  * @typedef Header
@@ -286,12 +287,17 @@ class Headers {
 
   /** @param {HeadersInit} [init] */
   constructor(init = undefined) {
+    if (init === _brand) {
+      this[_brand] = _brand;
+      return;
+    }
+
     const prefix = "Failed to construct 'Headers'";
     if (init !== undefined) {
       init = webidl.converters["HeadersInit"](init, prefix, "Argument 1");
     }
 
-    this[webidl.brand] = webidl.brand;
+    this[_brand] = _brand;
     this[_guard] = "none";
     if (init !== undefined) {
       fillHeaders(this, init);
@@ -486,7 +492,7 @@ webidl.converters["Headers"] = webidl.createInterfaceConverter(
  * @returns {Headers}
  */
 function headersFromHeaderList(list, guard) {
-  const headers = webidl.createBranded(Headers);
+  const headers = new Headers(_brand);
   headers[_headerList] = list;
   headers[_guard] = guard;
   return headers;