Changing criteria for showing badges in object timeline view

Summary: Ref T8941

Test Plan: Create an object and create multiple transactions, some time apart to ensure that time clumping isn't interfering. Make sure that events that are large enough to have a dropdown menu show badges under author pic.

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin

Maniphest Tasks: T8941

Differential Revision: https://secure.phabricator.com/D15543