Send an event when a notification is dismissed

[dshokouhi]

Fixes: #418

When a notification is dismissed we will send mobile_app_notification_dismissed event along with the message as part of the event data.

Example data:

{
    "event_type": "mobile_app_notification_dismissed",
    "data": {
        "message": "test",
        "device_id": "DEVICE_ID"
    },
    "origin": "REMOTE",
    "time_fired": "2020-10-06T05:36:12.864583+00:00",
    "context": {
        "id": "ID",
        "parent_id": null,
        "user_id": "USER_ID"
    }
}

Docs: home-assistant/companion.home-assistant#352

[JBassett]

We should probably be consistent with what we send into the events. We normally send the whole data object we receive with the notification not just the message.

[dshokouhi]

I had to do some conversion in order to pass data properly, but now we get everything :)