Bugfix: [LDC-572] Add exposed filter Workbench state

## Ready State: Yes

#### JIRA Reference: https://imagex.atlassian.net/browse/LDC-572

Add exposed filter Workbench state.

## Deployment Instructions

* Merge code.
* `drush cc all`
*  `drush views-revert admin_views_node`
* Clear caches with `drush cache-clear all`

## Usage/Test Instructions

* Browse to `admin/content`