Native persistent notification until read

Currently on Windows 10, chat notifications are shown in the Action Center, but disappear after a delay (user controllable in Action Center settings).

I believe the right user experience would instead be to have the notification persist in the Action Center until the related message has been read (at least locally, but better would be if read on any device). This dismissal should happen even if the user doesn't directly interact with the notification in the Action Center, to avoid a proliferation of notifications. The user would still be able to dismiss a notification (keeping the related message unread).

This would mirror how notifications work on Android.

The [HTML5 Notification spec](https://notifications.spec.whatwg.org/#persistent-notification) on which the [Electron notification feature](https://www.electronjs.org/docs/tutorial/notifications) is modelled allows for such persistent notifications. However I am unclear if the Electron implementation supports these persistent notifications.

No repository file, test, or entry point is named. Start by checking the Electron notification implementation and the linked HTML5 persistent notification specification; done means notifications remain in the Windows Action Center until the related message is read, while still allowing manual dismissal without marking it read.

Written by the indexing model from the issue text.