When a user is awarded a badge they don't appear to get notifications (emails) about being awarded a badge.

I am importing this task to upstream from the original request made by a different user in the Wikimedia Phorge (formerly Phab) installation.

The request is to introduce functionality that notifies users when they are awarded badges.

Please also see details at: https://phabricator.wikimedia.org/T270405

ways to reproduce:

• Award a badge to a user.
• expectation is that the user will get (e-mail) notification. (email in brackets because a user can change how they get notified generally)
• Instead, no (e-mail) notification is sent.