Move xwiki-platform-statistics to XWiki Attic

Sure! That’s an interesting topic.

It’s really implementation details but we don’t need any new concept for this, just a dedicated filter.

Yes on this side, it’s already take care of but how do you know what to filter out? (ie how to write your filter).

There’s different options. Easiest is to use a by convention a dedicated application name for the events we don’t want to output to users: the filter would then just check this application name of the event.
Now if we want to allow using same mechanism for extensions and we don’t want to reuse that application name to allow using different names for extensions and XS for example, then we can use a dedicated custom parameter in the event that we can check in the filter.