Modularize workboard column transactions
Summary: Depends on D20279. Ref T5474. Modernize these transactions before I add a new "TriggerTransaction" for setting triggers.
Test Plan: Created a column. Edited a column name and point limit. Hid and un-hid a column. Grepped for removed symbols.
Reviewers: amckinley
Reviewed By: amckinley
Maniphest Tasks: T5474
Differential Revision: https://secure.phabricator.com/D20286