Extract notification to own package

[williamleven]

Email notifications should be extracted to their own package

[williamleven]

Would probably be a good idea to use Gotify

[Portals]

Isn't Gotify in use not? @williamleven

[williamleven]

Nope: https://github.com/cthit/goldapps/blob/master/internal/pkg/services/admin/password.go