Converting badge recipients from Edge to BadgeAward table

Summary: Ref T8996, Convert badge recipients from Edges to actual BadgeAward objects

Test Plan: Create badge, award it to recipient. Make sure adding/removing recipients works. (Still need to migrate exisiting recipients to new table and need to create activity feed blurbs)

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: chad, Korvin

Maniphest Tasks: T8996

Differential Revision: https://secure.phabricator.com/D15014