allow notification display and management

[yuvalif]

this gh extension: https://github.com/meiji163/gh-notify
allows for commandline interaction with notifications.
would be useful if this could be integrated into gh-dash, so the display and interaction are done using TUI instead of commandline, and are fro mthe same tool

[joshmedeski]

I think it would be great to integrate GitHub notifications (in general) into gh-dash.

@dlvhdr let me know if you'd be down for me to do some work on this. I'd recommend we design the UI first.

[dlvhdr]

Of course I'm down, sounds great!