Notifications

[Ewoutvans]

• Give notification if version gets approved of project (I don't need notifications when I make my own release #367)
• Don't give notifications of plugin upload if uploaded the plugin (I don't need notifications when I make my own release #367)
• Redesign notification page (its broken on mobile)
• Give notifications to owners of organisation if someone accepts / declines
• Give notification to owner of project when admin changed a page (or made a page invisible Staff-side Improvements #329)

Anything I'm missing?
I'll be working on this if I have time this week

[malte-laukoetter]

It might also be interesting to add Push support to the notifications so it's not necessary to open up ore to know if there are any new notifications: https://developers.google.com/web/ilt/pwa/introduction-to-push-notifications