Clickable notification title when click.url is set

[DVDAndroid]

Is your feature request related to a problem? Please describe.
If I send a notification with this extra set:

{
  "extras": {
    "client::notification": {
      "click": { "url": "https://gotify.net" }
    }
  }
}

the url parameter is only available on the Android app (only when the notification is pressed, then its value is lost, I may implement this on the Android side, too)

Describe the solution you'd like
Make (at least) the notification title clickable with the extra parameter in the JSON payload

Describe alternatives you've considered
Leave as it is

Additional context
I can send a PR

[jmattheis]

I'm not sure, client::notification describes the notification and not the message itself. IMO it wouldn't be obvious that it affects the message display. I also don't know if that's really necessary because you could add a link to the message body and use it instead of using extras.