Allow to filter the event types to display in the notifications macro

Currently, the notifications macro (https://extensions.xwiki.org/xwiki/bin/view/Extension/Notifications%20Macro/) allows to be used as an event stream macro, configured to display the events for a given scope (wiki, space or page) - when useUserPreferences parameter is set to false

However, in this usage, it's not possible to configure the events that are to be displayed in the event stream. It should be possible to filter, inclusive or exclusive, the events to be displayed by their type. Usecases:

• excluding mention events from being displayed in the event stream - see also XWIKI-18698 . Mentions are rather "personal" information and it makes a lot of sense to be able to exclude them for a usage that is not contextualized to a user
• only displaying the events from a given application (e.g. Blog events)
• etc.