Modify PublisherNotifierUnverified
Modify PublisherNotifierUnverified

* Remove unnecessary attributes :notifications_params, :notification_type

* Change `perform` to use a case statement on the publisher type, remove redundant `return`

* Tell GetWhoisEmailsForDomain service to use `domain` instead of undefined `@domain`

* Remove unimplemented `perform_youtube` and add TO DO comment

Refs #372

brave/publishers,dgeb/publishers,brave/publishers,dgeb/publishers,brave/publishers,dgeb/publishers