[feat] Implement interacting with each notification separately

[fnune]

Currently the only write action is "Mark all read". I was hoping that this application would allow me to finally quit GitHub's Notification UI. For that I would need at least a "mark as read" button on each notification.

Thanks for the cool app!

[rafaelmardojai]

I see. The desktop notifications do have a per notification mask-as-read action but I didn't add that to the window interface.

Sounds like a reasonable improvement.

[fnune]

I see. I haven't had a chance to see the desktop notifications, yet 😄

With that, I could see why the in-app functionality isn't a priority. But probably still good to have.