Why:
There are Notifications with associated `notifiables` that actually are
not anymore Notifiables (the class doesn't include the Notifiable
concern). So when Notification delegates certain "notifiable" methods
to them the is an error.
How:
Using `try` directly on the notifiable association to avoid the delegate
trap on those corner case scenarios.
The notification body has been extracted to a new partial to allow
notifications without link to be rendered without needing an if-else
duplicating view code.
Note the `link_to_if` at _notification partial, as well as the optional
body attribute.
