Bulk actions pings and update monthly contributor definition

Created by: malomarrec

We recently added bulk to allow users to manage a large number of changesets in just a few clicks. We don't have metrics for them yet.

• We want to track usage of bulk actions.
• We now consider that users that perform some bulk operations (comment, merge, close, publish) are actively managing batch changes and should be counted as monthly contributors.

RFC 424 APPROVED: Add server side and bulk actions to Batch Changes pings

• add count of the number of bulk [comment, detach, re-enqueue, merge, close, publish] by week
• update monthly contributor definition to add any user that performed a bulk comment, merge, publish, close in a given month