Fix vite sample application [2 XMR]
Currently, the [vite sample application](https://github.com/woodser/xmr-sample-vite) supports loading a keys-only wallet in the browser and displaying its keys.

However, http requests [fail to send](https://github.com/woodser/xmr-sample-vite/blob/112c887787758643261603aed3392899b1c59ef5/src/index.ts#L28):

```
TypeError: Cannot read properties of undefined (reading 'call')
        at m.sendJsonRequest (index.js:478:11292)
        at async T.getHeight (index.js:496:42372)
        at async tA (index.js:505:106455)
```

And [http requests fail to send within the web worker](https://github.com/woodser/xmr-sample-vite/blob/112c887787758643261603aed3392899b1c59ef5/src/index.ts#L37):

```
TypeError: r.g.fetch is not a function
        at h._onFinish (monero_web_worker.js:2:1543631)
        at e.exports.<anonymous> (monero_web_worker.js:2:1542602)
        at a.emit (monero_web_worker.js:2:1007398)
```

This issue requests fixing the vite sample application so it fully works with monero-ts.