* feat: Adds a webhook for when a user follow the stream Frontend: Adds a checkbox which renders only when social features are enabled. Backend: - Defines a new type for the event - Implements the webhook including unit testing - Fires the webhook inside the ApproveFollower handler * Removes unnecessary Type fiels from Events struct * refactor: renames SendUserFollowedEvent func to FediverseEngagementFollow and fixes linting errors * fix: fixes unit test to reflect removed Type field from FediverseEngagementFollowEvent * feat: fires webhook also when manual approvals are not required * chore: slight cleanup --------- Co-authored-by: Gabe Kangas <gabek@real-ity.com>