Move search, new room into thread column in Conpherence

Summary:
Moves search and new room out of crumb bar and into the thread column. This opens up space to add "Edit Room" into the crumbs area as an action link. Also removed 'widget-edit' pathways and javascript.

Fixes T8972

Test Plan:
Search, New, Edit rooms. Click different rooms, see correct URL each time.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T8972

Differential Revision: https://secure.phabricator.com/D16543