R1:60157ed40d6e

Move general workboard actions to "Manage Board" dropdown

Summary: See D9719.

Test Plan:
- Used hide/show columns.
- Used "add column".
- Filtered board.

{F170133}

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9726