Render linked JIRA issues with a Doorkeeper tag

Summary: Fixes T3687. Instead of rendering "JIRA Issues" in Differential using plain links, render them using Doorkeeper tags so they get the nice "enhance with object name" effect.

Test Plan: {F84886}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3687

Differential Revision: https://secure.phabricator.com/D7648