Don't render a grip on tasks returned over AJAX to non-draggable UIs

Summary:
Fixes T5140. When you ajax-edit a task and we send back a full-size card, we currently always put a drag grip on it.

If you clicked the "edit" thing from a priority-ordered list, this is appropriate. However, if you clicked it from some other type of list, it is not.

Pass the expected grippableness through the call.

Test Plan:

• Edited a task from a reorderable (priority-ordered) view, got grip.
• Edited a task from a nonreorderable (author-ordered) view, got no grip.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T5140

Differential Revision: https://secure.phabricator.com/D10282