Suggestion: Possibility of passing params to apps
lgtv2 has a possibility where you can pass "params" when launching an app. For example this can be used to launch youtube directly to a certain video by using special link

Example:

```
lgtv2.request('ssap://com.webos.applicationManager/launch', {
	id: 'youtube.leanback.v4',
	params: {
		contentTarget: 'https://www.youtube.com/tv?v=Bey4XXJAqS8'
	}
});
```

This will open YouTube app directly to the example 4K video.

This would be great to be used in inputs. How I did it locally (modified homebridge-webos-tv/index.js)

1. Added "Demo 4K" input with `"appId": "youtube.leanback.v4|https://www.youtube.com/tv?v=Bey4XXJAqS8"`
2. Modified setAppSwitchState so that it does `appId = appId.split('|')` and if `length > 1` use `com.webos.applicationManage/launch` with `{ id: appId[0], params: { contentTarget: appId[1] }}`
3. Modified checkForegroundApp like: 
```
if (appId === undefined || appId === null) { // if appId undefined or null then i am checking which app is currently running; if set then continue normally
	callback(null, true, res.appId);
} else if (res.appId === appId) {
	callback(null, true, appId);
} else if (res.appId === appId.split('|')[0]) { // This is the added part
	callback(null, true, appId);
} else {
	callback(null, false, appId);
}
```

So now I have switch named "Demo 4K", which when clicked opens the Youtube app to 4K demo video

This is a crude way of accomplishing what I need, and there must be a better way to do this.