onnxruntime

[js] changes to allow Float16Array if any polyfill is available (#19305)

### Description

This change adds only necessary code to enable ort-web works with any
Float16Array polyfill. Unlike #19302, in this PR, ort-web does not
include any specific polyfill; instead, it's user's choice for how to
use a polyfill.

ORT-web uses Float16Array if it's available; otherwise, fallback to use
Uint16Array.

```js
// case 1: user does not use polyfill:
import * as ort from 'onnxruntime-web';

const myF16Data = new Uint16Array(...);  // need to use Uint16Array
const myF16tensor = new ort.Tensor('float16', myF16Data, dims);
```

```js
// case 2: user use polyfill:
import * as ort from 'onnxruntime-web';
import {
  Float16Array, isFloat16Array, isTypedArray,
  getFloat16, setFloat16,
  f16round,
} from "@petamoriken/float16";
globalThis.Float16Array = Float16Array;  // ort-web will pick the global Float16Array

const myF16Data = new Float16Array(...);  // Use the polyfilled Float16Array type
const myF16tensor = new ort.Tensor('float16', myF16Data, dims);
```