Notification forward plugin

[pankleks]

Add possibility for end-user to inject notification forward plugin (js file) -> for example slack

[rohit-gohri]

So, this will be something like an option in the config where we can specify path to a js file that will be dynamically imported and will act as a Notification Handler?

If so, then there could probably be an implementation of a base class/handler that we can export and one can extend.