[Test-Proxy] Breaking Change - Move `AllowAutoRedirects` to `Transport` customization

Now that we can customize the client used on a per-recording basis, we really should move the `AllowAutoRedirects` option that is currently at the surface level of the request body to `Admin/SetRecordingOptions` into the `Transport` object.

What this means:

Current:
```
POST /Admin/SetRecordingOptions

{
"AllowAutoRedirects": true
}
```

After

```
POST /Admin/SetRecordingOptions

{
"Transport": {
"AllowAutoRedirects": true
...other transport settings like certificate
}
}
```

We will allow the passing of header `x-recording-id` to offer users the ability to allow redirects on a single recording, while allowing all the others to continue working without that customization.

I believe that @timovv currently uses this functionality for the js livetests. However I end up modifying this should be also pushed into `main` with the PR that updates the test-proxy version.

TODO
- [ ] Move AllowAutoRedirects into `Transport` and test
- [ ] Add new key for `Insecure` flag into `Transport`