Add Column Edit / History actions to workboard columns

Summary: This brings up "Edit Column" as an action item under the main column dropdown as well as a "Column History" for completeness. Unsure column history is actually useful, but leaving it in anyways. It might be nice to have some sort of dialog version of a history page.

Test Plan: Make a workboard, add a column, edit column name, stay on workboard.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D17874