Encoding issue while pointing to local AEM instance

### Expected Behaviour
HTML page should be properly rendered by proxy server when the proxy points to local AEM instance and local AEM instance uses the proxy server for hosting Site Theme.

### Actual Behaviour
Actual: HTML page is not properly encoded and contains "Â" characters instead of " ".

### Reproduce Scenario (including but not limited to)
In our project setup we are using Front-End Pipelines & Site Themes and we would like to use proxy server that points to local AEM instance. Additionally, on AEM side we would like to use the proxy server to host the Site Theme (theme.css, theme.js).

#### Steps to Reproduce
1) Create sample site called `mysite` on AEMaaCS Author instance
2) Enable Front-End pipeline for `mysite` on the AEMaaCS instance
3) Create Front-End pipeline in Cloud Manager and run the Front-End pipeline for `mysite`
5) Go to the Package Manager on the AEMaaCS instance, create package with `/conf/mysite` filter, build and download the package
6) Recreate `mysite` on local AEM Author instance and set up front-end project (e.g. based on https://github.com/adobe/aem-site-template-standard-theme-e2e)
7) Go to the Package Manager on the local instance and install the downloaded package
8) Go to CR/DE on the local instance and change `prefixPath` to point to local proxy `http://localhost:7001` in following node `/conf/onexp/sling:configs/com.adobe.cq.wcm.core.components.config.HtmlPageItemsConfig/jcr:content`
9) Open any page in `mysite` (e.g. `/content/mysite/us/en`) the local AEM instance and add Text component containing space character (e.g. `Example of text message. `).
10) Starts the proxy server and open http://localhost:7001/content/mysite/us/en.html in browser
11) Observe incorrect encoding for space characters `Example of text message. `.

#### Platform and Version
aem-sdk-2022.6.7904.20220629T070041Z-220600

#### Sample Code that illustrates the problem
In `proxy.js` there is following code that if HTML does not contain any link to static CDN domain for Site Theme (e.g. https://static-p12345-e12345.adobeaemcloud.com/1234512345123451234512345123451234512345123451234512345123451234), the HTML is not modified and response contains incorrect encoding for ` `.

```
proxyRes.on('end', function () {
const data = Buffer.concat(body);
const html = isGzipedRequest ? zlib.unzipSync(data).toString() : data.toString();
const replacedHtml = html.replace(/"\s*?(http|\/).*?\/(_default|[0-9a-f]{64})\//g, '"/');
const isHtmlModified = (replacedHtml.length !== html.length);

if (isHtmlModified) {
try {
res.setHeader('content-encoding', '');
res.setHeader('content-type', 'text/html');
res.removeHeader('content-length');
res.end(replacedHtml);
log(`Proxy ${requestUrl} with modified theme artifacts.`);
} catch (err) {
error('Something went wrong. Proxy html rewrite error: ', err);
}
} else {
res.end(data.toString('binary'));
log(`Proxy ${requestUrl} without changes.`);
}
});
```

Our suggestion for the fix would be to use `data.toString()` instead `data.toString('binary')`:
```
proxyRes.on('end', function () {
const data = Buffer.concat(body);
...

if (isHtmlModified) {
...
} else {
res.end(data.toString());
....
}
});
```

#### Logs taken while reproducing problem
n/a

Start in proxy.js at the proxyRes end handler and compare the unchanged-response branch with the modified-HTML branch. Reproduce the local AEM scenario using the listed steps, then verify that the rendered page preserves spaces without introducing "Â" characters.

Written by the indexing model from the issue text.